I have played with XRP on the transaction network with peercover, snapswap, and other gateways... it has not matured yet. I have yet
to figure out how to convert XRP into cash in an easy, affordable and reliable with any of the trusted gateways. Until Ripple does get its act together, might as well use BTC as your main trading currency and do your instant cashing out with Coinbase.
I am investing in XRP as a commodity for now, like BTC and LTC. I think it could bring huge payoff, because the players beyond
XRP are big venture capital folks, including Google. They have a lot to gain when XRP climbs in value with the billions in premine.
I'm actually talking more about the fact that you can send USD, EUR, BTC, LTC, NMC, COYE, DOGE, or whatever else across the ripple network. Again, I don't really have an opinion on XRP as an investment. I don't think XRP has any real value, except to facilitate transactions. The processing network however is amazing, imo.
Ripple is still a very complex, high priced way to convert currencies until it becomes more established, when the trusted gateways have more volume and are reliable.
For now, I like using BTC as the main trading currency between exchanges, which you can convert instantly to cash via Coinbase.