So I'll give this a shot since I've been to all three this week, I'm not even close to an expert. Also, really sucks to not to be able to see drills this year, kind of hard to focus on each player during scrimmage:
Kostin: His speed looks like it's about the same but his acceleration improved. Puck protection is still there and used his body a lot to shield players from the puck. Seemed like he's gotten better and more relaxed as camp has gone on. He found a few soft spots in the slot today but didn't bury those chances. Had a nice breakaway goal yesterday. His hand are good made some very nice moves today.
Bokk: Good lord does he have hands. His passing is very good, looked like he was getting frustrated at points when some of the invitees couldn't handle his passes. Defense is an area to improve on, which is usually the case for young offensive players. His skating was very good, gets up the ice in a hurry. I wish he would have shot more in the first couple days, he seemed defer a lot, but today he shot a lot more. Don't think he had any goals though.
Perunovich: Skating and passing are his best attributes to me. His speed, acceleration, edgework seemed better and more noticeable than last year. He walks the line very well and could usually get around his man. His passing is great, he always seemed to find an open man, just wish he would shot more. He's probably shot less than 10 times in 3 scrimmages. He has good stickwork in the d-zone which makes up for the lack of size, usually going directly at the opposing player and applying pressure. Seemed like he won more battles and was stronger on his skates than last year.
Toropchenko: He looked like he put some weight on since last year. Dude still flies down the ice and also was back-checking which was nice to see. It seemed like when he was out there he was never in the defensive zone, so don't have anything on that. Has good hands and has gotten stronger on his skates. It was great to see him out there with Kostin, they seem to mesh well.
McGing: He has speed for sure. That's about all I noticed out of him, it's a good thing he's going back to college.
Laferriere: He seems inconsistent to me, Alexandrov and him had a nice tic-tac-toe passing play one minute, then I don't know if I noticed him for the next 10 minutes. Kind of reminds me how Barbie was when he was a prospect. When I did notice him though his passing was always tape to tape. Don't really remember him shooting the puck either. His skating is decent with average speed. Hopefully he can put up some big numbers in juniors next year.
Alexandrov: Haven't really noticed him at all besides the nice passing play above. If I go tomorrow I'll try and watch him more.
Washkurak: So far he's looked better than Alexandrov. He's a good skater with some speed. I see why he got that work horse award this past season. Kid works for the puck non-stop. Gets in on the forecheck and backchecks as well. He went to the net a bunch. His passing was pretty good. He seems like he'd top out 3/4 liner, PK, chip in occasionally on offense.
Hofer: I thought he looked very solid. First day I don't think he let up a goal in scrimmage. His lateral movements were good, made a couple of back-door saves. He made some nice breakaway saves as well. Didn't really handle the puck too often.
Tucker: By far the most improved player from last year for me. Seemed like he was out there the whole time. His skating has gotten a lot better, but still wish we could watch the skating drills. He still isn't the fastest guy, but it seems like his first few steps have gotten quicker allowing him to get up into the play more. His offensive game has greatly improved. His hands and puck control seemed something that he worked on over this past year. At one point he dangled through two people and got a nice shot off from 5 feet out and my mouth dropped. Defensively he's pretty solid, his stick work was good and played the body well (could definitely tell he was holding back). He always seemed to be in the right position minus some breakaways on the 3v3 part of scrimmage. He seemed to play a lot more than the other two on his team, so he did looked gassed in 3v3 a lot, so maybe work on stamina?
Invitees that impressed, that I could see us targeting: Copeland, Curry, Jackson, and Hrabik.
Well there you go hopefully that helps. Wish I could give better details than that. Hopefully some other posters with some better knowledge can post their thoughts.
PS: Krag and Helt haven't really done anything.