For me i would rather buy more Ripple (XRP) Why? Theres a lot of confusion about this company but if you can separate the fact from fiction, the opportunity becomes clear.
Keep in mind that altcoins, including XRP, are more risky investments than Bitcoin, which is already risky enough.
I know that Ripple team is trying hard to move the price up, but the money flow into altcoin scene is limited for now.
I think that for now Bitcoin would be a better option and maybe at a later point a switch to altcoin(s) would increase the gains.
But that's just speculation, please use your own calculations when you invest money for real.