Tough call - both very solid restaurants. I'd say look at the current menus and see what's more appealing. The cuisines are somewhat similar, though SPC throws in a few more fusion-y flourishes while Rose Water is pretty solidly "New American" with the local/seasonal thing. No yuzu on the menu there. If you're partial to pasta, SPC generally puts out some good ones.
Also, if you like cocktails or a sip of something hard after your meal, Rose Water is strictly beer & wine as I recall.
787 Union St, Brooklyn, NY 11215