My #1 bass guitar since about 1995 has been a Yamaha TRB6P. I also played acoustic upright with a pickup and an NS Design 6-string electric upright. I played a wide range of covers as well as jazz trio and big band. I also bowed the upright through an amp in a classical style.
I prefer amps that would be considered more transparent and high fidelity. I like a sound that is clear and focused. In general I find that strong lows tends to degrade clarity and focus, so I often wind up with a fairly lean sound on stage and a fuller sound when practicing at home.
I never really embraced the idea of having an extremely small rig for home practice. I typically just used whatever I had available.
The rig I bought for [personal] gigging was a GK 700RB/112 combo. I bought this amp because it was the best I could find at the time what would fit in the trunk of my Dodge Neon. I also demoed the 210, and preferred the 112. It was barely loud enough for work with a cover band, so I started using an extension cab for louder gigs. I think the 115 version of the combo would have sounded better, but it wouldn't fit in my car and I never came across one that I could demo.
My last touring rig in the military was rack-based. My rack had a tuner, a Furman power distro, rack drawer, QSC USA 900 power amp (260W x 2 at 8 ohms), and an Ashly MX508 rack mixer. The cabs I had available where 8 ohm Eden D210XLT and D410XLT. I typically used only the 210. I stacked the cab vertically on my rack, with a DI wedge under the front edge so the cab tilted back to aim at my ears.
The D210XLT was louder than the GK and was also a lot more clear and focused down low. I liked the high range of the GK better and mids, lows, and extra headroom of the Eden better.
The touring rig was big, heavy, and packed in rolling flight cases. It's worked great as we travelled with a cargo truck that had a lift gate. Usually we rolled the gear out at stage level. So it was short push and then I took the lids off, stacked the cab, patched the cables and I was ready to play.
The touring rig was not very practical for smaller gigs were we travelled in a 15 Pax van. I had the organization buy a GK 700RB/112 combo, just like the one I had at home. I used this rig for jazz trio and also all of my rehearsal needs. This meant I did not need to unpack the rack rig.
After I retire from playing, I went berserk collecting amps. I am at over 50 at this point. Most of them sound good a lot volume, but a few really need to be cranked. My Hiwatt DR201 and Mesa Eight:88 Strategy fall in to this category. So these amps are not really ideal for home practice. Some of my amps also have fairly obnoxious fans. Vintage Ampeg SVTs and Marshall VBA 400 are probably the worst. A lot of people complain about the fan noise from amps that are much quieter.
Another factor to consider. My collection is pretty varied. I think all of the amps sound great, but they don't necessarily suit the tone goals I normally pursue. My tonal preferences tend to fall towards the blackface era, Fender tone universe. So while I think my SVTs and Hiwatts are incredible, they probably would not be my choice for gigging unless I was really shooting for a specific tone, rather than simply dialing in the sound I prefer.
Another bit of context: I generally had full audio support, so my stage amp only had to satisfy my needs. Our audio tech typically took a DI off my bass and dialed in the bass to suit the mix.
I don't think you can satisfy everyone's needs, so I would suggest figuring out what you want to achieve. Some people, like myself, prefer more transparent rigs and some prefer more voiced rigs like an SVT through an 810.
My perception is the market is focused on value, performance, and keeping size and weight as low as possible. I also suggest keeping the fan noise as low as possible.
I think using a modular system approach would be a good call. So if you are making combo, you would have something that is small, light, sounds good, gets reasonably loud, and can be expanded. If you decide to make a range of different cab configuration, put in the necessary engineering in to make them all mix and match. In other words, users should be able to choose randomly from a 115, 112, 212, 210, 410, etc and all combinations should be safe and sound good together.
