disclaimer: These are just my opinions, I have no idea what I'm talking about.
www.ampwares.com has alot of info
Dont get the Hot Rod series, they have serious known problems, like weak resistors, shotty speakers and input jacks, cheap failing relays. My band's guitarist has one and it has been nothing but trouble. I've also serviced a Hot Rod deluxe that just simply ran too hot and the components will unsolder themselves. They are also made in mexico where the evil twins are made in usa. They don't sound bad, they are just a maintenance headache.
I dont have experience with the old red knob twin, i suspect they are of higher quality though, because the '94 protube twin amp [PTTA] has really thin wiring and also cheap-o parts, and then the newer PTTA (with trem) has pc board mounted sockets and just a poorer design in general, although trem is nice, the newer one is a servicing nightmare. But all that said, its a great versatile amp with tons of features and basically every thing i need/want all in one amp (except for trem). I own the '94 ptta, and it sounds good, it's got pretty good fender clean and fender reverb. The distortion might seem crappy for some, but I dont use it that often, and it sounds good to me, i guess it depends what kind of breakup you want, this doesnt have the late compressed break up a lot of blues players love, I use my 8 watt for that. BTW dont use the 1/4 power switch, it honestly doesnt do much, 3db difference, and it tends to fail, and has often, just leave it at 100 watts.
The biasing is a joke on these amps IMO, they tell you to bias really cold on the Hot rods, but really hot on the evil twins. Dont trust those values on the back. Use a bias calculator and plate voltage to get the right bias (from a red plated experience)
With all this said, personally I'm a vintage fender junkie, and if I could start over again, I would first get a smaller handwired vintage like a champ or a princeton, vibrolux, pro-reverb. You can really get a feel for the play in volume and tone with these amps, they are easy to service and will last you a long time. They will retain and gain value and mod easily if you're into that. You'd be surprised how loud 10, 25 watts is! if you like the idea of a distortion switching, try the rivera series fenders, the princeton II, twin reverb II, deluxe II. Those are quality handwired amps as well and any tech will be happy to service these amps, and probably charge you less because the vintage amps are all so similar and it will take him (or her) much less time to fix it. It's also easier for you to look inside and folow a schemo and understand your amp.