I've used them both, and really, I don't see any practical difference in a 38 SPL, though I do tend to load most of them to the hotter side. Clean, efficient, both of them, and in this area of Pennsyltucky,, the cost advantage is very slightly toward the Titegroup, though YMMV. (That means for comparable velocity, I save maybe $.01 or less per shot for TG).
I know someone is going to ding me for being a tightwad over that, but when it comes to being a skinflint with a 38, I'll shoot 148DEWC's over 2.7 gr of Bullseye. I don't think it could get much cheaper - but your original question was leaning toward +P, so HP-38 (231) or Titegroup do the job admirably - flip a coin for the choice. BTW, they work well in 9mm, 40, & 45 quite nicely, too.
If you are trying to extract maximum out of 2" barreled revolver, Titegroup probably would have the edge in results (can't say for price) and I have gotten good results with 700-X which is very, very near Titegroup on the burning rate chart, though it does not meter as nicely as TG.
My personal observation is that 700-X gave less flash out of the 2" than slower powders did, particularly at higher velocities, which seems kind of counterintuitive..
Flash