It's about time I've changed my bass strings.

Currently, I've got some Roto Swing 66's...love them. But, I've also heard great things about Dean Markley Blue Steels.

They both come in the same gauge that I desire, but I don't know how they sound in comparison to one another.

(I play metal, but I'm quite slap happy.)
Hmm, I stand by DR strings. Every one of their strings I've tried has done magic to the tone of my basses. I'm currently using DR Lo-Riders which are great for a low-mid grunt, I also recommend D'Addario, Thomastik-Infeld (great strings), Sadowsky, and LaBella (which are primarily known for their flatwounds).
I've heard good things about DR Lo-Riders. I am currently using D'Addario's and I am not happy with them. I think they sound horrible.