Yamaha DTXpress/DTXplorer/DTXtreme

I am talking about single rolls on the snare.... i have always been 
doing them with only downstrokes.... i found out yesterday about 
upstroke / downstroke technique. In other words one hit when the 
stick goes down and one hit before it goes up.

Is it harder to perform on rubber than a actual drum?
 
I guess that tecnique is the only way to get blistering fast single 
rolls. 

And another question conserning the kicktower... ive heard that its 
harder to get fast rolls on them than a usual bass drum because 
there is not as much rebound from the kicktower. Have i heard right?

Thanks