the answer to the OP is a resounding YES! at least in my experience ...
had some free time over the weekend and dug out an old Mullard 12AX7 i had stashed and a 1985-vintage Groove Tubes 12AU7 (back when they relabeled older production tubes) and popped 'em into the Brick ... i expected maybe a slight improvement, but it was more like the preamp found a bigger voice. all the qualities of the tube experience were magnified — depth, warmth, and subtle but sweet compression.
i retracked a background vocal, and now it's got me wondering if ought to go back and retrack all the vocals ... reinventing the wheel!
... i probably won't, but i was surprised at the difference. of course YMMV!