Amplifiers weight


What does amplifiers weight has to do with performance?
im trying to decide between this 3 amps
parasound JC5 73 pounds, Anthem STR 60 pounds Michi S5 by Rotel 132 pounds 
I can get them around the same price 
my speakers is modified klipsch KLF 30
preamp is Michi P5 and a pair of SVS SB16 ultra Sony Hap Z1 and Cambridge Azur 851N
i really like the looks of STR amp 
128x128lordrootman
My single ended Dennis Had Firebottle amp puts out 12 to 17wpc and weighs a massive 15lbs. Sure, it seems like I should reinforce the floor for the thing, but somehow I get by fine...15lbs...if it was dropped on your head from 10 stories above I'd want it back as hey, who the hell is dropping my amp from 10 stories up? I hate that.
@dseltz thanks for the response my 2 channel set up is including 7.1.2 HT in family living room with kids so definitely no tube amp I will be interested to add tube preamp in future 
I really love the presentation of SS and tube preamp combo 
Looking from a prospective I think a manufacturer who will implement both correctly will win at the end of the day 
Lord...more weight not necessarily better for sound, reliability etc. Weight only comes into play for me if I have to move the thing around.