Sam,
I prefer tube power over solid state, in a perfect world. I have two 200-watt mono all-tube power amps, which sound better than any other power amps I've played through, period. When I push them really hard they make anything seem to sing. They also generate enough heat to warm a medium-sized room in precious little time. And they weigh a lot. Imagine one of the old Peavey CS-800s filled with cement and that's how heavy each one of these seem to be, and in addition to that they are mounted in made-by-me 3/4-inch plywood racks with lots of heavy reinforcement (to deal with the weight) and cooling fans. HEAVY. They must sound pretty good for me to haul them around, which I do, except for those days when I simply can't face lifting them so I take the solid state stuff instead. And to think I built a house with stairs...
I agree with Joey that simply having a tube preamp shapes the tone and envelope enough for most people and/or situations, given that the power amp is clean and has plenty of headroom.
From what I have personally heard, many integrated heads are just as quiet as component setups, and without the added problems associated with cabling everything together and cable failures. It does pay to give whatever you're thinking about using a listen, because unit-to-unit there are usually some differences in the noise floor, even with the expensive stuff. I have an ancient POS Peavey Mark III head which is perfect for noisy dance halls with a swing band. I wouldn't use it in any studio, because it's rather hissy.
As I posted earlier, I use a Bass Pod Pro. I really use only a few of the gazillion features of the unit and could totally be happy without the effects section. Fast switching between amp models and settings is something whose time has come. I wish it had an Ampeg V4B model, because I've gotten great sounds out of every one of those I've plugged into without having to work at it. I'm most impressed with my little ART tube preamp, which I think I got for $40.00 at a hamfest (ham radio, not the other white meat) flea-market awhile back. It's quiet and very musical. For the years I used an F2B, I had a broadcast EQ unit in the signal chain before it, so that I could have more control over the lows. The F2B-ish preamp I later had built deals better with the lows, but not as well as the Pod or the ART. The F2B is one hell of a nice guitar preamp. I get more and more interested in the Superfilter whenever I read these pages, so hopefully one of those is in my future...
So by now it's obvious that I like to mix and match, which I wouldn't be able to do with an integrated head. I also use the integrated head more than I would have expected, because it is a well-thought-out compromise (which is more than I can say about most of my playing!).
Speaking of playing, I *LOVE* Peter Cetera's tone on Dialogue Part I. And that bass line is absolutely brilliant. I wonder what he's doing these days. - I am annoyed by great bass players who sacrifice bass for singing...
John