I have a Scaremaster (same thing) and a Indoor Survival. They are both good boards. I am interested enough to try a Indoor Survival FK for sure. The Scaremaster is fun and I pretty much just use it for days more spent on boxes/rails etc. The IS I have is cambered but still a lot of fun all over and good pop. Can't say I love either anywhere as much as the Evo-R though! 2 diff technologies though. I may sell all my cambered boards this year!
Few kids are on the stairmaster and stairmaster extreme at my hill and they have nothing but good things to say about them. I anticipated them being really soft noodly boards but I was surprised with how solid they were and how much pop is in them. I prefer the ride of a sintered base myself.
I rode a Capita Indoor survival 2 seasons ago, what an awesome board! I loved it, probably not as much as my current board though... GNU Street btx. I have rode a few friends Stairmasters and they were great too. Pretty much second what everyone else has said about it above.
Capita make some of the best boards on the market IMO.
Me and my friend both bought our first Capita's this year (09 Black Death and 08? Travis Parker) and after a whole season of abuse we're so happy with them.
My boards taken some massive hits (rocks, tree's) and held up very well. Kills it in everything.