Also very much in this camp and also on the lift 170. I have tried higher aspect wings, and prefer the lower aspect wing shape in spite of its noticeable drag. The 170 is very similar to the 633 in planform. That low aspect shape is just the nicest to go rail to rail down swell. Have tried small higher aspect, med higher aspect, same size much higher aspect and larger but same low aspect and have settled on 1100 cm2, thin profile, low aspect with big stab and short fuse. Really couldn't be happier than the Lift 170. Too bad they don't make it any more!
Much less drag on higher aspect wings, but thats only really needed for glide in the upwind carves with a kite. The added drag is not really much of an issue headed down swell and really rather helps keep you in/on the wave. Really, its a variable that you get used to and though there is more drag to the Lift 170 than there is to say the never V2 150 surf, it's not a game changer amount like it is going from say surfboard to foil. These spade shaped foil wings absolutely provide enough glide to carve swell in perpetuity where a surfboard in gutless small swell, not so much. Higher aspect wings also have wider wing spans and that eventually limits the rail to rail carving as you start venting the tips. There is definitely a sweet spot and on my 82cm mast I don't want a wingspan much above 66 cm.
The speed envelope for good rail to rail carving in swell is moderate to slow, which really suits wings with a very soft stall that you can essentially ride through, where the higher aspect wings with more glide, will buck you off at stall speeds. You can get pretty fed up with that pretty quick! I personally carve around a lot at lower speeds as our waves are just not that fast, so much prefer med/low aspect main wing. Stall can be felt starting and even just a quick pivot is enough to get you out of it.
Thin profile is one way to help keep excess drag to a minimum.
Stab size and fuse length are also key pieces. I like a short fuse and pretty big stab. At slower speeds it provides a lot of rear foot feedback while carving and feels much more like a good surfboard than a higher aspect wing with smaller stab. If you ride bigger swell at higher speeds, my set up would be too locked in. That big stab makes it hard to carve anything but a drawn out turn once the speed is up.
So, my happy place: 1000-1200 cm2 for average weight, med aspect wings, thin profile, short fuse, decent size stab, moderate mast length, super light board and Peak4s on relatively short lines.