what differentiates tube integrated amps?

Kind of a generic question, but there seems to be a fair number of chinese built $1500-2500 el34 or kt88 tube amps such as line magnetic, prima luna/mystere, cayin etc. They seem to appear to have the same features +/- and not too much to distinguish from each other. I guess with anything it's different strokes for different folks, but solid state amps seem to have wildly varying specs at similar pricepoints whereas these amps have similar specs at the similar pricepoints.