I agree that the MR/ROV25 tone is similar to the Single, and not like the Dual or Triple.
I disagree about the "real deal" comment. The Single and MR are different from the Dual and Triple, but no less "real". Just different.
I think that for the lead channel, or the clean channel pushed, you would stand a chance at keeping up with double bass unless the drummer is just a beater. For actual clean, 25W just won't hold up.
I have gigged my RV25 all on its own with acoustic rock drums and had no trouble with volume, but honestly had it pretty much flat-out. I usually run a direct to FOH using a Radial JDX, which completely eliminates the need for more power and does a wonderful job of controlling stage volume.