My ideal transistor amp would be non-switching - like my little Sugden A21a - but bigger and not integrated - I prefer total discrete monoblocks - so 6 needed for my pair of 3-way dipoles which have 3 pairs of binding posts each with an outboard crossover.
I like chunky amps like Krells, Pass Labs, Mark Levinson, Karan Acoustics, Vincent, Accuphase , Luxman, Nakamichi - My Gryphon Diablo 300 I gave to my brother was gorgeous - it was a party animal but could be delicate and subtle.
So I like big discrete toroidal transformers, big but fast capacitors, star - earthing, 90 degree phase shifts, fast rise times, high slew rate, high damping factor, 10 db of headroom.
I like amps that can do under 1 ohm output - but not many can.
I`ve had 20 watt amps that could do over 200 watts for 50 microseconds.
I like a lot of real power going to the speakers - 20 -50 amps is nice, 100 amps is better like my old Musical Fidelity A370.
Most 1000 watt AVR`s are less than 20 amps - toytown.
I love battery preamps and monoblock valve preamps because there`s less compromises.
I`m looking at Chinese bespoke high-end esoteric genuine class "A" transistor and Valve amps now - Why ? because every switching amp I`ve had heard including £20000.00 ones sound slow to me - I`m a tenor sax player.
I like speaker and amps that can turn on and off very quickly - in other words transients with alacrity - like my Danley DTS-10 horn sub which is very naughty.
My five foot wide subwoofer can do 15Hz - 70Hz at well over 127 db - continuously and cleanly - it peaks at 133 db - it`s not like a $3000 domestic SVS or my tiny 100 litre BK Monolith + FF which is more than five times smaller and less than a third of the weight.
I don`t mind if the extreme bass and treble is imperfect as long as the midrange is holographic.