So, a couple months ago, I decided to get a new amp for rehearsal purposes, but also possibly as a personal monitor on stage. I did some shopping around, and saw a new 50W keyboard amp from Vox, the VX50KB. Unlike other Vox models, this has no internal modeling software. It's a straight up 3-channel keyboard amp with Korg's "NuTube" technology. The speaker is 8" coaxial.
It's a pretty decent amp so far, and has served me quite well, gets plenty loud for rehearsal. Might be okay for a quiet venue, as well, but I don't know that it would put out enough volume for a larger, louder rock gig. Might work okay as a personal monitor in that situation; I have yet to try that, but plan to in the near future.
Each channel goes through a master EQ section. The 3rd channel can be set to mic or line level, and also has a phase switch which can be helpful. The thing only weighs about 9 lbs. and is highly portable. No battery power, just a power supply, which can limit it for any buskers out there.
Sound quality, I was pretty surprised in a good way. I get decent pretty balanced tones out of it for most of my keyboard needs. Acoustic piano can be kind of hit and miss, but can be adjusted to be acceptable via EQ. My organs, electric keys, synths, and drum backing tracks (for when our drummer is absent) sound quite good through the amp, and put out a decent enough volume. My Nord Lead 2X also sounds quite good through this amp. The speaker is only 8" coaxial with bass ports, but I've found it puts out enough low end to meet my needs so far. Then again, I'm not pulling keyboard bass duty either.
Some keyboard amps have trouble running a guitar through them, for understandable reasons. I run my guitar though the pedal and into this one, and as far as I can tell, it sounds fine, and I've had no troubles with it at rehearsals. I also round my mic on the 3rd channel since I sing harmony in a few songs, and other than needing to adjust the EQ to avoid feedback, it has been just fine for me. (My mic is a Shure Beta 58A)
The amp sells for around $230 USD at most vendors. I got mine a bit cheaper as an open box item that was mint (shipping brought the cost back into the $200's though). In comparison, my 100W Carvin 1x12 3-channel AG100D acoustic amp was about $430. But it also weighs like 40 lbs.