^I agree with Chrish, I think most of the good replies to this thread have been geared towards faster solvers. He may not be using f2l so any f2l look ahead comments may not apply. Around 1 minute you just need lots of practice to get quicker recognition and execution of everything. Lookahead gets key as you get faster but isn't absolutely necessary at 1min imo.
On topic, I think using the slower cube may improve your times with the storebought, but may throw you off when solving the faster speedcubes. You might start overturning, popping, or in general messing up triggers n stuff. I would say take your main cube, and take care of it. Don't let it get lost or stolen. If you are really worried about it getting lost, broken or whatever then you may want to take a storebought you don't really care about.