Ive owned and played them all, and all running through Ampeg Pro Neo 115 and 410 4ohms. The B2re, 450 watts at 4 ohms is easy to dial in, its does the classic Ampeg tone really well, not a one trick pony but close to it. These are pretty cheap, they are really reliable but sometimes since they are older the solder joints sometimes need to be remelted on the PCB board, which isnt that big of a deal. The V7 is 700 watts at 4 ohms with a preamp tube, it has a lot of flexibility with the B15 and SVT modes with that it makes it harder to dial in that classic Ampeg tone. So you can get many more tones out of it, but the classic tone is harder to dial in and it sounds thinner to me than the other amps. The SVT 7 Pro is 1000watts at 4 ohms, it is really easy to dial in (start everything at 12 noon) and gets the classic Ampeg tone, turn the gain up and it gets the thick, beefy, and refined SVT ampeg tone. The V-4B is all tube and stock its 100 watts and 60#, the others are pretty light. Stock are 7027 tubes and you can upgrade it to 6550 tubes and that gets you about 130 watts, I had one I did that too. The 7027 version is a classic thick classic Ampeg SVT tone, with the 6550's its thunderous, and probably close to the output of the SVT 7 pro. Tone 9/10 B-4n and SVT 7 Pro, 7/10 B2re, 6/10 V7....but I want the classic ampeg tone so the V7 maybe better for you if you dont.....Hope this helps!