What are the weak points of Pass amps and pre-amps ?

They are not expensive compared to Gryphon, FM Acoustics and other Swiss brands, or even some Japanese, I guess.
Yeah, those lights would bother me, that's BS. Big and heavy, all good amps are big and heavy and inefficient.
Not enough top end resolution and energy - now this is a weaker point.
Being on a slightly warm side of neutral is a strong point for me. Redgum amp that I have is exactly that, good balance.

buy used Pass amp and pre and they will hold their value incredibly well, so not so expensive in long run...I owm X250.8 and XP-22...actually ended up spending very little on the used X250.5 and XP-20 that I traded in after owning 4/5 years...

Does everyone prefer class A Pass amps overall ? Both current and older.

I prefer the X series, though have not heard the top of the line XA...my dealer said many prefer the X to the XA at given price point...

That's unexpected. Could you say more why you prefer X series ?