Have either of you listened to both out of the same speaker?
Well I have and I still do .........
speakers - Revel Studio II's
tube amp(s) - Rogue Audio M-180 monoblocks
SS amp - Plinius SA-102
The 'richer' sound that you mentioned is apparent with respect to the bloom of the midrange (euphoric distortion I believe some call it), depending on speakers the bass may not appear as tight and the upper freq somewhat rolled off. It all comes down to the synergy (amp design specs vs. that of the speakers)
In my case I just can't part with either, I love em both and for obvious reasons the M-180's get used more in the colder months.
As for the maint. issues with tube amps it's way overblown. Yes, tubes will not last forever, but 6-10,000 hrs for signal tubes and half of that or better for power tubes is a lot of musical enjoyment. As for biasing the power tubes, it's a piece of cake on the Rogue's. After the initial 50 hrs they required a small adj and have been rock steady ever since.