To come back to the original question -

I recently bought Champion Go ~CrazyStone~ for Android (On sale for $2.99, I think regular price is $7.99 -- Either way I figured it was significantly cheaper than a book so worth a try). On a dual core 1 GHz tablet I would estimate it's strength at the strongest level to be about 2-3k KGS, and I can't recall it ever taking more than 30 seconds for a move. I would imagine the computer version is stronger on just about anything considered "standard" hardware these days (If the large-cluster version on KGS is about 4d, you can probably try to scale where your hardware fitss on that spectrum to get an approximation) -- though the computer version is significantly more expensive, I think it may have more features too though, I can't speak for it...

I don't have any answers to the update questions mentioned up thread.