Patagonia Ascentionist 40 vs. TNF Phantom 38

Looking for a technical Ice/alpine pack, something that can be low-profile enough to not get in the way but also carries well enough to haul rope/rack/tools etc. some camera equipment and potentially gear for overnight missions. I'm really torn between the two, the Patagonia seems a little more lightweight and low-profile, but the North Face Phantom has a few nice features lacking on the Ascentionist (sleeves for tool picks, fully removable brain and waistbelt) and seems like it might handle loads a bit better, which is important for that bulky, heavy camera equipment.

Anyone have any experience with either? Thoughts, impressions, full reviews all appreciated.

You may want to give the Mountain Equipment Tupilak Pack a look.  I don't own one, but I looked into one hard at the beginning of the season and they get phenomenal reviews.  Super lightweight, on-route alpine packs.  If comfort is more what you're looking for, take a look at Osprey's new Mutant series.  Some people love the Ascensionist Pack, and some hate it.  

I ended up going with an Arc'teryx Alpha FL 30 for an on-route winter alpine pack and so far, it's been great.  Arc'teryx just dropped their brand new Alpha AR 35 Pack. If I was doing anything where I was hauling more gear ie: stove, tent, sleeping bag, etc. on technical routes, I'd probably order a Tupilak.

I was in this boat not too long ago, looking for a good technical alpine pack. I can't really stress fit enough. A pack can have all the nicest features and the lowest weight, but if it doesn't fit you well, you'll still be miserable in it.

I looked at several packs:  Patagonia Ascensionist, TNF Cobra, Arc'T Alpha FL, Gregory Alpinisto, Osprey Variant, Osprey Mutant, Black Diamond Mission, and Black Diamond Speed.

The Speed quite simply fit me the best. Alpine packs typically don't have adjustable torso length (weight), but the BD fits my back perfectly, so that's what I went with. Loaded it up with 30 lbs in the store and carried it around for about half an hour while I looked at other stuff just to make sure. Highly recommend trying stuff on with weight if you can, whether that means ordering several packs and then returning, or finding a store that has a good selection.  

I do have some other general thoughts though. I thought I would really like the Ascensionist, but I didn't really like the closure system or the fact that it's less strippable than other packs. I can get the BD speed down to just a tube with some shoulder straps if I want, and I like that flexibility. I think you're kind of hitting on that idea noticing that the Phantom has a removable waist and brain.

I use the BD Mission 45 for most climbing use. It pretty big for a 45l in my opinion but the strippable design and removable brain is super nice. If you plan to do more hard climbing with a pack on, maybe get the 35 or a speed. If you carrying it mostly on approaches, occasionally over night I highly recommend. 

I was debating the same, since these packs are at a steep discount on backcountry.  Looking at both and reading reviews both packs have drawbacks.

3rd option I feel cilo gear 30 guide is worth the extra money for me.