I rest my thumb on the e string when playing something on the higher strings, but my instructor drilled it into me that that 'sweet spot' is where I should play slap :p
Nothing wrong with practice amps, I don't need a big amp as at band practice in drummers house everything I need is there, saves me spending a ton of money prematurely
i think Chris Wolstenholme of Muse uses one, i was also thinking of buying one to try and get that sound, can anyone say whether it is the right one for Muses sound?