well, for a start i go to shops etc during the week (absence of other customers), good time to try anything you fancy.
It really depends on what you want from your amp. In the case of the 'rat' i wanted that valve crunch at low levels, but i didn't want to be listening to the buzz and humm of badly placed, cheap components.
a boutique amp was out of the question for home practice(££££)
I had heard of , and researched rat amps, my prob was hearing one, which eventually i did...sold!!
The peavey serves a different purpose, extremely loud, keeps up with the drummer, no fragile valves so its more suited to lugging around and bumping about. real spring reverb which sounds ok..the 'crunch' channel (like most electronic amps is a bit poo..but its not an issue it's just for practice and you can always stick a pedal on the clean channel..which is highly detailed and superb!
never seen an amp that does it all, and all cheap amps have 'issues' some can be easily sorted just by ripping out the (usually) crappy speaker and putting in something bettr...if i was gigging i'd be using a valve driven amp, and you can be sure i will want to know what its built like, what components are used, and which factory produced it.. before i even turn it on!!.
you cant rely on a brand name these days.