I recently bought a new old stock (NOS) Vox VT30. I like this amp a lot. I like the variety of sounds I can get out of it and it can be LOUD. I took home a VT15 for a week or so to check out and I brought it back and got the VT30 that they had. The VT30 is a lot nicer in my opinion, and yes it is fairly loud. You could jam with it, straight up, in a lot of situations, even with a controllable drummer you could be loud enough. The range of sounds is really great and the controls are easy to get some great sounds out of it with ease. I use the amp every day and it is very responsive to the controls on the guitar. Some of that digital stuff takes the guitar controls out of your hands and renders the tone controls on the guitar useless, the VT30 lets you use the tone controls on the guitar to help shape the sound, which is very nice. It also has great response to pick attack, which is also great.
I wouldn't hesitate to get another VT30, I wouldn't, however, get a VT15 probably at all, unless I was going to use it for some reason where I needed a very small form factor amp. Maybe for camping trips at places with electricity, vacations, or other reasons where a small but durable amp, protected by a heavy chrome speaker grill, would be good to have. I'd go with the VT30.
I heard that the VT50 "Chromie" is mega bassy, to the point of not being able to EQ the bass out of it enough to get a decent sound. Some people that are knowledgeable of these Valvetronix VT50's and VT30's say that you can "greatly" improve the sound of the amp, such as the excessive bassiness of the VT50, by putting a small pillow or other insulation inside the amp around the speaker. They talk about this on the forum -
valvetronics.net . I tried the VT50 out and it was indeed super bassy and there was no way out of the bassiness with the EQ or whatever. As I said, I have the VT30 "Chromie" and I like the way it sounds; the sound is EQ'd very well with no excessive bassiness. I have not stuffed a pillow or other insulation inside the amp. It sounds really great just the way it is. But the insulation idea is something to read about on valvetronics.net in order to find out more information. Supposedly almost all of the problems that the VT30 could develop can be easily eliminated by doing a simple "factory reset" of the highly computerized amp. Just like a home computer needs to be rebooted now and then, these amps sometimes need to get rebooted, but not unless there is a reason to do so. You don't just do a reset for the fun of it.
I hope some of this information helps you out. I had been wanting to get a "Chromie" for a long time and I'm glad I finally got one, and I got it at a very excellent price, NOS. Good luck with your amp quest.
The VT30 is a very neat and fun amp that could be a great item for a lot of different people, but, of course, other people's opinions will vary.
I think it is very possible that you could be very happy with a VT30, based on my own experience.