Man I love looking at frames in a decent resolution, all that lovely grain and detail. I just wish Team Negative1 would do the same as you and post some frames from the reels they're working on in a decent resolution like these frames here to get us all excited.
That ICE does do a great job but with a bit of eyeballing on my part, I can definately see a loss of sharpness, albeit its very subtle but most importantly the grain is still very much there, pretty much exactly as it is in the original frame.
With a slight sharpen filter applied you should be able to get the ICE frame looking like the original frame, in which case I would personally go with scanning it with ICE enabled because it does look much cleaner and so many defects every frame could get distracting when the video is in motion. It's not like ICE gets rid of all the defects either, just the most noticable ones so you'll still have that cinematic feel. :)