Experience with automatic card shufflers?

I play a lot Dominion lately and while I don't mind shuffling the deck at all, the degree of randomness from a manual shuffle seems kind of low. So I'm wondering if an automatic card shuffler is worth the investment. I can get one for around 50 bucks which seems an okay investment if it does what I want: quick shuffle and better shuffling than manual.

Does anyone use these, what's your experience?