Haven't tried Michelins, but I'm running conti gp4000s like everyone else and they've treated me great (NOT version II).
At equivalent PSIs, 25s have less rolling resistance than 23s. Less aero of course, but for what I'm doing, that is borderline irrelevant.
What it means for me is I can run my tires at 90-100 instead of 110-120. I basically have the same rolling resistance or BETTER AND i don't feel every single tiny bump in the road way more comfortable.
If you're looking at getting new tires, I wouldn't bother with 23s but that's just me.