I know you can trade through Bitstamp with the ripple.com client but haven't heard anything about MtGox being compatible.
It's not. The wiki was just using the name MtGox as an example.
But the spreads on Bitstamp are crazy high for some of the different currencies. They don't have much volume, so not much liquidity really. Hopefully that will change because it's nice to be able to trade between xrp, usd, btc, eur and other currencies in one place.
You mean "the spreads on
Ripple" ... Bitstamp.net isn't too bad (still a lot less volume than MtGox). Other than trading for XRP the volumes on Ripple are very low right now. It's still in beta after all. It is trivial however to whip your Ripple Bitstamp-BTC over to Bitstamp, sell it there, and whip the resultant USD back into Ripple as Bitstamp-USD (and offer it there for a profit or trade it for XRP or use it in a payment, etc).
