ssd on pcie

It seems that I can get msata ssd card these days, and a dual or quad pcie msata card (msata card mounts on the pcie card), and save myself a bunch of existing sata ports and other server real estate. I have a server that doesn't have a lot of disk bays and I want to start using bcache again, but not with just a single ssd (want to do writeback so need raid1), so this seems like a reasonable option. Are there any better options for a similar price? Thanks James