Jon,
A most excellent review of some very high quality quena's!! Thank you dearly! There is simply not enough discussion on so many wonderful world flutes and I rank the quena and quenacho up there as some of the most versatile flutes in the flute world.
I've heard quena's play Irish Jigs, Classical, jazz on top of it's Andean roots. And I follow the makers in S. America closely to watch for new developments and idea's and hope they get incorporated here.
I am familiar with all those makers as I have the same Ellis Quena, a healthy selection of Angels quena's and one custom quenacho and I did have an Acha Quena and Quenacho which are no longer part of my ever growing collection. They didn't look like your nice wooden one there as they looked like the mass produced bamboo ones sold on Bolivia Mall. They were some of my first quena and quenacho. The quenacho holes were so big that my fingers almost went inside the flute. But another guy on Chiff and Fipple also said he had great experience with a custom flute from Acha.
First, we all know that Geoffrey embodies a true world flute spirit as he is as comfortable with Native American flutes as he is with Irish Flutes and having read the discussions here in the past about his Irish flutes and making the grade, I can say that is entry into the quena world IMO is a raving success. I'm personally very happy to have an American flutemaker of high quality flutes making quena's and hopefully in the future other key's including quenacho's. I know alot of people are hesitant to buy foreign made flutes but I've purchased flutes from Bolivia, Peru, Argentina mostly with no problems. And even one from Paris. One exception where I did encounter a problem but not important right now. Suffice to say that Interpole as an APB out on him

I've spent hours upon hours researching this instrument and seeking out makers wherever they might be so I've accumulated quite a stash of different types of quena's.
LIke any flute, each has it's charm and different styles can be used for different types of music. One quena is just not going to cut it for all kinds of music.
I guess it's fair to say that the tapered quena is not traditional. However, they do have some quena's that are made with a reverse taper or a globe that have become somewhat popular. I've tried one but the notch was very very small so I couldn't give it a good comparison. I will have another chance to try a few in a couple of weeks when a Bolivian maker comes to New York for a performance and promised to bring some Ebony quena's in different keys for me to try. The last thing I need is one more but I guess for the sake of completeness, if I like it, I'll add it to my collection. For some reason, he gets a very reedy sound for ebony and the globe doesn't encourage ease of playing. I've noticed clarinet makers now incorporating similar design.

I will agree that Geoffrey's quena in the usual Ellis tradition is finely crafted with attention to detail. I don't take that for granted because I've gotten quena's with splinters hanging out of them by other American makers. Bore and outside lacquered with his special technique. I have no problems bringing it up to 3rd octave C. And it might go higher, it's just I haven't focused on it with any quena. The bigger problem is how do you make music up there although I've heard a couple of guys go up to 4th octave. It can sound a little bit like a balloon letting out air.
His quena does have relatively small finger holes compared to most of my others. But I don't think the volume suffers because his notch is a little wider than most. I would call it a C, notch. V, U and complete squares which are the pre-Columbian notches that give a very beautiful tone but cut down on the range. I think the wider notch in this case compensates for the smaller holes because I have another one with similar smaller holes that I can't go up into the third octave. A lot of that Andean music requires third octave G's and A's so traditional or not, it can do that job.
I do have a background in jazz music which I just can't escape from so I also do like big finger holed quena's, within reason to get chromatics and clean 1/2 hole notes.
As for Angel, I have quite a few of his quena's my favorite being a straight cylinder Guaycon quena. It has an extremely sweet sound with some nice overtones. And I really like that groove he puts in the finger holes so the fingers lay in perfectly and it does make it easier for chromatics. I actually just experimented doing it on one of my Peruvian closed hole models without runing it. Came out quite nice. It is a nice feature, a preference, and not at all necessary. Also, Angel is a very reliable person and so nobody should have any fear doing business with Argentina. His art work on the notch is always exquisite. The bamboo he uses which I was told by a shakuachi maker is actually cane. I don't know. Does have a lot of trouble lasting through cold New York Winters and the resulting tone is much reedier. So unless I move to Miami, no more cane flutes. Some of the larger bore instruments get into extreme stretch tuning where the top note can be a chromatic tone or more off and playing modern music with that can be difficult unless you adjust the playing angle.
So Angels quena's do have a very wide range of plus's and minus's. They might be a little challenging for beginners. Some of them I love and others I don't. And it is not the first quena I pick up. Ellis quena is always in my bag. I prefer Angels' his medium and larger bore but do have a a couple of his small bores that I used when I began.
I'd use Angels quena more for new agey stuff
http://youtu.be/280dmeJmB8Q I played one of his chromatic quena's which is a little swiss cheesy but I wanted to try one.

I don't think that many holes are necessary if you have bigger holes. It is also a small bore like the one you have. Apparently a chromatic quena doesn't work so well on medium or larger bore instruments.
I could see using his bigger bores in an Andean band. Playing Virgenes de Sol where you need that third octave G and A to ring out
http://youtu.be/3-nucgiyddQ I do think big holes gives a little more burden to the player to control the volume up in the higher register using more back pressure but on a song like that you need to cut through the ensemble.
Anyway, I hope to do a lot more recording with Geoffrey's quena soon. I don't like sharing unfinished pieces but I'm sure nobody will hold it against me. The poo's and phoo's are not the quena. It's the player at 11:30 at night after loosing multiple recordings after the cord got pulled out and they weren't saved. The mastering is pitiful but the improvisation is pretty good if I may say self myself. If Miles Davis can make a career out of poo's and foo's and wrong notes, I'm sure one recording on a quena review won't ruin my career. It's a jazz improve on Sting's Fragile using Geoffrey's G quena which looks a lot like yours. I think mine is a curly maple but a bit darker. I'm real bad with remembering woods. I didn't record the melody on quena but used a NAF so just the quena improv. Better with headphones and a couple beers.
Sorry, I don't have a pic of it but I can add one tomorrow;)
ps: I guess I should mention the blowing end is the angled embouchure not the straight edge. Again straight and angle are matter of preferences and comfort. I'll take either. Angled you play more downward.
https://soundcloud.com/flutetests/fragilepractice