Moving up from NL10/20 to 25/50 and/or 50/100

I've been playing on party poker 10/20 NL full ring since they opened up the tables and been a very consistent winner and lately made a few changes that I think has made my game even stronger. I feel like I'm playing really well and wanted to maybe try moving up in stakes, but not really sure how tough the games are at the 25/50 level and up. I was wondering if some other people that have made this move could help me out with some of the differences between the levels and sites. I've found 25/50 games and higher on UB, Prima, and FT.. are these the only sites that offer these stakes and if so are there typically more/softer players on one site than another? Are the games very beatable or is it typically a few sharks trading money with slim advantages/disadvantages until the occasional fish trys his chances? It seems like with the very low amount of players playing at these stakes almost all of them would tend to be very good and make their living off poker as opposed to the PP 10/20 crowd... and in terms of making money playing against weaker players at lower stakes might even be more profitable and I'm sure more consistent.

Also at these levels the games are typically shorthanded, which I think I do ok at but I'm sure I'm much better 8-10 handed since that's what I've played 99% of the time. I'd be fine with learning to play shorthanded I'd just hate to find myself at a table size I'm not 100% used to at stakes I'm not used to with other players I have a small or no advantage on.

Anyway, was just hoping some players that have played at that level could give me some advice, thanks in advance