When Tyranny comes knocking.

[jumpy]

^^

me ma swears by it - she cooks meat and veg, curries and all sorts from scratch. obviously you don't get the nice 'crackling' on meat etc but it works ok.
She's really anal about the leccy bill so I guess there's a decent comparison if only anecdotal and not entirely scientific..
There's a few google searches that seem to indicate cost vs time comparisons with traditional stoves and microwave cooking.