Having two SSDs in RAID 0 almost doubles sequential read and write performance. But one SSD would be better than two in terms of reliability. Considering SSDs reliability in general, I'd say the benefits of a RAID 0 config out way the downsides.
wow sequential reads and writes go way up that really helps....NOT. Sure it grabs textures at 800MB/sec then, but access times rises because you do it in software raid and guess what that nearly negates the raid0 and it only worsens if the files are small. I don't think a second in load time will be worth it. Heck windows didn't start faster here when I tested it with two Samsung 830's. Even upgrading from an Intel Postville to a Samsung 830 didn't improve that much. Sequential read and write is only great for marketing but says little for real world performance.
You'll be far happier with more memory, a GPU upgrade or anything else.
If you really want to profit from higher speeds get a recent PCI-e SSD or an M2 SSD because those bypass the pci-e to sata conversion overhead which helps out with the small files a lot.