It's really hard to compare them. They are somehow overlapping, but Stellar has a better consensus protocol and it allows the technology to be open. To join ripple you need to sign some papers and get approved, but with stellar anyone can join. I think that this significantly lowers the entry barrier.
With Lightyear.io stellar is also trying to get "heavier" enterprise clients. I can clearly see what Stellar is doing and what they are trying to be (crypto cheap SWIFT), with ripple it's more complicated. I don't think there is a place for ripple. The clients that Ripple has right now are not using them to solve real problems, just experimenting. But with stellar you can actually go to an anchor give them money and get it on the network. And soon Stellar will overpass Ripple with their client number.
Of course nothing of this means that the price of Lumens (XLM) is going to overpass XRP. It's still crypto and prices are just made up and manipulated.