haha. Welcome to k-con!
This'll be my second kumori-con; my fifth convention overall. (I too, went to sakura-con)
The hotel staff isn't THAT bad, I think we just overwhelmed them last year. The biggest problem was just that they didn't know where to put all of us and it frusterated con-goers and staff alike. Just be nice and understand to them and they will more than likely do the same for you. In my experience, they weren't anywhere near as mean as the angry lady that always runs the escalators at sakura-con. O_O she was scary.
The first thing you have to realize is that K-con is WAY different than sakura-con. The atmosphere is totally different. It's so much smaller and more communal. There is less space, but more time to be spent talking with other con-goers or going to events or hanging out down in the shopping area. Also, I find it WAY fun to walk around portland with my group. If you think people have no idea what's going on in Seattle during sakura-con; you haven't seen anything yet. It's amazing! But always go with a group! It's so much safer.
Points of note. The artist alley and sellers, at least last year, were in a really weird part of the building? their in a parking garage, off to the side of the hotel and it's kind of hard to find. Also, because of fire safety laws, they had to regulate how many people could go in and out of that area (and several other areas) and so there was a line. If you wanna shop, do it early, or plan time to wait.
Kumori-con is much less an event based thing. Like at sakura-con I find our group running around every which way to get to events. Kumori-con has a lot more down time which I prefer, as I like love crowd watching. But I personally enjoy the anime dating game. It's much more Pg than the sakura-con one, and it's wonderfully hilarious. DEFINITELY GO. Most of the other events I attend aren't happening this year becuase guests phil and kaja pholio aren't going to make it this year to the event. Which makes me a little sad, but alright.
My first year at kumoricon was amazing. REally fun, but go into it with an open mind. It's really a lot diffeent from sakuracon. But the fun and the people are all the same. Crazy. ENJOY!
Cheers.