1- Market cap XLM $11,584,161,743 XRP $70,767,891,304 Stellar has more potential because do not need another $70,767,891,304 to double the price just need another $11,584,161,743 to double it
2- Price XLM 0.63 XRP 1.80 Stellar has more potential because it has smaller value and looks cheaper
3- 1 year growed XLM 0.0015 - 0.91 60566.6% XRP 0.0053 - 3.28 61786.7% Almost the same but ripple waited too much 0.20-0.24 range while XLM was mooning and that was so boring for XRP HODLers
4- Storage Both - Ledger wallet Just fine.
5- Marketing XLM - Seldom and not much know yet but it just started XRP - Very often and mostly you can here.
XRP has nice company and CEO backing it up but people talking about it too much and there are even haters out there its so speculative, You can see people making charts about XRP 10$ and 0.1$ at the same time which is making no sense. XLM has seldom news on twitter or internet. I have never seen any body on TV from the XLM. And in Tradingview not much charts as XRP has.
Conclusion: Both nice coins but in the short term XLM has better potential. XRP needs more total market cap to grow thats the biggiest problem other than that you can buy both.