My limited experience is with my Dryad Orion, it's a recurve with a 19" riser (but not ILF, it's Dryad's proprietary design). I have two sets of limbs, both ACS.... one set are 'longs' at 45 lb and the other are 'mediums' at 50 lb. Now, those are the marked poundages, but on my 19" riser, they are somewhat less (the 45 limbs are actually 42.5 lb at 28", the 50lb limbs are actually 48 lb at 28"). My draw is 30", so the 45 is actually 46 lb at my draw and the 50lb is actually 52 lb at my draw. I suspect they are both spot-on if mounted on a 17" riser, but I don't know for sure.
I've done extensive testing with various bows, including older classic bows with dacron strings and slightly more modern recurves with a low-stretch string. All shooting with fingers either over a light chronograph or next to my LabRadar.
The Dryad is definitely my fastest bow. By comparison, I have a super kodiak that is 56 lb at my draw - the dryad, with the long limbs (46 lb at my draw), has the exact same cast as the super kodiak. Granted, the super kodiak has a dacron string, and the dryad has a very skinny string make out of (I thinnk) "Fury", whatever that is, but still that's a startling difference. Compared to my Wes Wallace Mentor that's 53 lb at my draw, the 'long' limb dryad (46 at my draw) is about 3 fps slower; for all practical purposes, they are the same. And I think the Wes Wallace is a fast bow.
I cannot say for sure if there are any issues associated with the dryad ACS limb - it's a static limb with carbon and has some pretty sever hooks. I have read that these types of high-performance limbs are more sensitive to a poor release, but I cannot verify that. The Dryad seems LOUD to me, but to those around me they tell me it just sounds like a regular recurve - I suspect higher-performance limbs may be more challenging to shoot quiet. The force/draw on the dryad ASC limbs are noticeably flatter than anything I've ever shot before.... uncanny really. A very smooth draw.
In conclusion, I really like the limbs/bow, it's a great shooter, and it has allowed me to drop poundage and still maintain a pretty powerful bow. Are the limbs worth $660? Well, if you want to drop 5 to 10 lb in draw weight and maintain the same cast, I think that's how much you'll have to spend. At least as far as ACS limbs go....