The Valvetrain Brandywine is a lifetime-built unit that sounds great (in an Ampeg-like way) and has a very satisfying amount of "oomph" for its modest 50W rating. I got it hoping to use with upright bass. I'm still working on that, but I wound up using it a lot on rock shows with moderate stage volume. It exhibits the best of that all-tube responsiveness where I can go from thick & round to face-melting fuzz just from digging in. I can always hear & feel everything I'm doing without ever overpowering anyone else. (That's a gold standard for me. Extremely difficult - basically impossible to achieve for me with so many other bass amps!)
The tone controls are similar to Ampeg, but I really like the bright switch. Many are just scratchy or thin, but this one adds a lot of edge & presence. It takes my old P-bass all the way from "polite" to "raunchy".
There's a little more gain sculpting facility than I generally need onstage, including TWO controls - a variable pad and a post-power "governor" - that work the OPPOSITE from a regular volume control. (Turning clockwise reduces the volume.) Those may prove handy in the studio for enhancing - or avoiding - breakup.
A built-in XLR DI would have been nice (as would have been a built-in dummy load for silent tracking) but I can work with the dual 1/4" sends. One of them taps after the power section for maximum tubey goodness. I've had great results sending to larger house PAs with an external DI, or running a guitar cable straight to my small mixer. (The way I use it onstage, there really isn't a pre-master type send. That can be a hassle with solid state, but the overall musicality of the response here seems to make it much less of an issue.)
I used to have an Ampeg PF-50T. By comparison it seemed gutless with drums with sticks, and harder sometimes to get a good sound with. It was prohibitively difficult for my tech to access the internals & source replacement switches. (My tech hasn't had to look at the Brandywine amp yet - I expect it will be infinitely more friendly to wrench on if & when he has to.)
I also compare with an old Sunn 200s which seems to have loads more treble baked in (like a bright switch permanently on), and is a lot bulkier & heavier despite having a similar power rating. I do still use it and love it, but the Valvetrain is quite a bit more versatile and practical.