I speak from the experience of owning a B15N for about 25 years. Yes, sometimes I exaggerate for dramatic effect, just as many Ampeg fans exaggerate the virtues of their beloved jalopies, I mean amplifiers. But when I say I wouldn't take one back for a gift, believe it. In the old days, it was pretty good. These days, it's pretty pathetic. I wouldn't gig with one any more than I would gig with a Mister Mike.
It ain't just the peculiar tubes (OK, depending on the year), it's the practically irreplaceable transformers, the '50s I-don't-need-no-education design vibe, and the overall inadequacy to any modern task.
To compare the Ampeg B15N with the Mesa/Boogie Walkabout Scout is to compare a '53 Ford sedan to a Porsche. To be sure, lots of people adore the '53 Ford because they, or their family, or their grandfather, owned one, but I live in the real world, and I expect a lot more return on my dollar investment than the Ampeg gives me.
Oh yeah, and not to forget my manners: thank you, JimmyM.