We have channel mismatch of about 0.5 dB which seems to be typical of a lot of these tube products.
There seems to be a lot of lower price tube amps that cut corners to meet a price. They can't do the time consuming tube matching and fancy auto-biasing. The design and build quality match the price and the sound suffers.
And there seems to be a fair amount of really expensive ones that don't care about quality output; only about appearances and buzzwords that don't perform that well either.
In-between are only a small amount (often custom built) that spend enough to make the quality decent and avoid the flash in favor of solid build quality. But there isn't much money in producing those so we get a lot of either end of the spectrum.
I realize tube amps won't ever have the specs of solid state but I think the low end, corner cutting models and the high end all flash models hurt the reputation of tubes.