Received my Bluesbaby 45 HH (switchable high headroom version) last week and wanted to share my initial thoughts. I ordered it with the Celestion A-type speaker for a more American-leaning tone and got the switchable high headroom option as I mainly play jazz. I had been on a seach for a quality SS amp with real spring reverb for some time, and was very excited to stumble across the BB.
The build quality is top notch; tweed is well applied to the cab and the insides are very neat and tidy. Lots of thought has obviously been put into the small details, such as rubber feet to isolate the reverb tank from the cab and the toroidal output transformer which reduces hum radiation (you can sit on the amp and play a single coil guitar without detectable hum). Almost goes without saying for a SS amp, but it is also very light.
In terms of tone, my summary so far is that this is a very flexible amp capable of a wide range of sounds. For example, the EQ controls (TMB) have a very wide sweep and small adjustments have a big effect on the tone. There are also three EQ switches as standard; a fat switch for more bass, an EQ selector to switch between a blackface-style mid cut and a flatter mid range and a presence switch. As a jazz player who uses a telecaster and a hollowbody with P90s this flexibility is ideal, as I can make fast adjustments to suit each guitar. To get an initial feel for the amp's tonal range and sound quality I set it up side by side with my blackface Fender clone and could dial it in so I couldn't really tell the difference between the two when played clean. However, I could then switch the EQ setting of the BB45, crank the mids up, and have a very polytone-like sound as well. One of my tonal touchstones is the Ted Greene shimmering 'telecaster through a blackface Fender with lots of reverb', and I could get into this zone easily. I also managed to cop a pretty decent emulation of Mark Speer from Khruangbin, who I consider to be a great example of what a strat into a Fender Deluxe Reverb should sound like. A nice warm jazz tone with the hollow body guitar was also easily achieved.
Overdriven sounds are very nice and the breakup is extremely 'tube-like' (although I find this term a bit odd considering guitarists are willing to pay 400 quid for a King of Tone to plug into a vintage Fender Deluxe Reverb haha). You can definitely get the 'edge of breakup' sound and have dynamic clipping that responds to pick attack and guitar volume level. Just for giggles, and to really put this SS amp through its paces, I stuck a Katana in front of it and my Fender clone and really pushed the preamps. The BB45 almost performed better, and held together very well at high gain without getting too muddy or flubby.
For balance, the downsides I have encountered so far are no dwell control on the reverb (it uses a medium dwell tank, so it is not unmanageable, I am just fussy) and no effects loop. Although, I hear a new model is coming soon with an effects loop.
I know it may be controversial to say, but above everything else I am really enjoying being able to flick my amp on and instantly get the same tone I had when I last switched it off without waiting 30 mins for tubes to warm up.