Hmm, I actually kind of tried to resist the big tube head cult. I used a few solid state heads, including a GK MB500 Fusion that I liked a lot. But the guitarists complained about my tone quite a bit. I ran a 100W tube guitar head for awhile, and they complained a little less, but they hated, HATED its direct out tone, I wasn't fond of it either, and it was inadequate in power. So, I bought the Super Bassman (later model). I got a pretty good deal, and it's put an end to the complaints about my tone. Heck, on the day I got it, I plugged it into my Ampeg 4x10, and just gushed over the fact that it could nail the tones on "One of these Days" perfectly with the bass plugged straight in. I do not relish lugging it around, though. The few (very few) gigs we've had where the venue has someone to carry the gear, I've appreciated it.
The Peavey Musician mentioned earlier generally gets the same happiness with tone from my bandmates (nope, I'm not sure why). It's half the weight, but half the features (no post-preamp balanced direct out, mostly).
As mentioned before, about 1/2 the venues we play don't have the PA to match our stage volume for much of anything but drums and vocals. When we play one large enough to need the direct out of the SB, it's very nice to have - even though I have to check at the last second to make sure the sound guy hasn't switched it from being after the preamp - if you can't handle the gain of the preamp, you're going to HATE it when I step on the Big Muff or Super Fuzz or whatever I'm using tonight. I've you're just going to drop me out of the mix and I'm going to have to turn up my master to project into the room, let's get that discussion out of the way during the sound check.
But then again, I'm pretty happy with the direct sounds I get at home. I'm sure if nice-ish sound systems became the norm for the places we play at, I wouldn't be upset if I had to pick out a nice amp/cab sim to pack into a case instead of hauling around all the stuff I haul around already.
And on the third hand, I've been playing live for 30 years or so. Nice sound systems aren't becoming ubiquitous yet. So, I imagine I'll be hauling the head and cab for some time.