I used to gig with a 250w 2x10 H&K Bassbase combo and it had no problems keeping me in the mix in a 'pub' Rock band setting. However, though I managed fine, it would have been nice to have had more headroom/drivers, so I'd never say never but it does depends on the quality of the gear that you are using. If you are considering going to a stereo/twin stack, then I'd seriously consider [u]all[/u] of your options before going down that route as there are a multitude of ways of being heard effectively.