While ICM and Revell's reboxed Type II UBoats can build up into nice models OOB, they do contain many errors. The ICM moldings are better than Revell's Type VII's with finer handrails, and MUCH better 20 mm's, and have overall crisp molding and generally good fit (although the deck needs some shimming as it's a fraction of a mm narrower than the hull. However, problems arise when doing your homework for extra detail. That's when you find multiple annoying errors. It looks like ICM designers studied their drawings and plans, then smoked a huge doobie, and promptly forgot which details belong where! ICM have released two kits both confusingly called "Type II B". Both kits contain two variations of conning towers, so you could actually build a Type II A; B; or C... almost. Unfortunately, the details of the conning towers are mixed and confused, so that none of them are 100% correct. I'm currently building the Type II B (with lengthened tower for 2nd 20 mm Flak), but I had to cut apart towers from both kits and glue them together to make one correct tower. I'm in the process of making the cut line disappear.
As for the hulls, they look good, but also contain errors. Each succeeding Type II U Boat model had an increased number of flood vents so that neither of them are actually correct, as even the basic hull has insufficient holes. As the first kit contains what looks like a model C conning tower, maybe a C hull will also be forthcoming.
If you're not picky, either of the kits can be built into a nice model OOB, with just a bit of extra work.