What's the difference? Is one better Than other?

I have a pair of Miller & Kreisel S-150THX... Angled...
And a pair of Miller & Kreisel MPS 2510...

My question is, whats the difference and is one better than the other?
I am thinking of selling one of the pairs but I'm uncertain which one to let go. Of course, I would like to keep the best of the two models.

Any help, suggestions offers,,ha ha

Thanks guys