First it's important to note that Ripple is not a currency, it's a global payment network that costs virtually nothing to use. Within this payment network you can use any currency you choose. USD, EUR, YEN, BTC, LTC, PPC or any other currency there is liquidity for. I say this because it's important to know what you're investing in. It's not Bitcoin. It's a true protocol like http, not a single crypto currency.
Is Ripple actually gaining any traction as a payment network?
I've yet to see a single business accepting XRP or payment through Ripple network, or hear about any major/regular transaction going through it..
Are there any stats about this out there?
It's too bad Ripple is tied to Open Coin. As a payment system, it's pretty brilliant and has a lot of potential to be extremely versatile for payments/micropayments. But the supply of XRP is completely fucked, fuck holding it. At the same time, since Ripple has virtually no liquidity, there is really nothing to be done but trade in and out of XRP.