in the winter, yeah more so then outdoors, because it will be dead outdoors in winter.. lol. in summer, its unlikely. hpwever with a well trained and mature bonsai, the fastest growth possible isnt always wahts desireable. and what good is a bonsai if you cant enjoy it?
True, true. I guess how you enjoy bonsai depends on what kind of space is available.
I'm just saying, I wanted to keep my first tree inside so badly that I did so for weeks on end to the point of almost killing it, but now I keep my collection outdoors -- it's really helped me discover bonsai a lot better and understand how the trees grow and respond to natural events.