I use oblit, UA, and HB. I justify the HB glyph by being able to do a UA-HB-PS-BS-BS rotation when I need it.
Since I don't have threat issues, UA is the logical choice. I usually have 32k armor so UA is an additional 1600 over the unglyphed version.
If I had threat issues, I'd swap to RS because FS takes a GCD where RS doesn't. I have more RP than I can burn in the rune cooldown window if I just use FS, but if use RS, most of the time I don't have enough RP in the cooldown window to get two FS's in. I find that just using RS when it's up and getting in one FS and a HoW on the rune cooldowns works best for me.
Proud king of being one-shotted by a wet paper bag.