Hi
My home is under construction and im having the electrician prewire the rears, I was going to ask him to put some in wall wire to wall plates for the front L and R. Is there any disadvantage to doing this over having cables direct from speaker to amp resting on the floor?
So you're letting the electrician, who probably doesn't give a rat's butt about sound quality and proper installation technique for audio/video cabling, do the job? Having worked around many, many electricians, I can say that they receive little to no training WRT noise induction, future-proofing an installation and proper terminations. The only ones who know/care already do low voltage installations and/or came from the low voltage field. The other ones have an interest in A/V, so they checked into this beforehand but most electricians have no idea that passing high voltage wiring near low voltage cables can cause all kinds of improper operation and weird problems, especially if they're run parallel in close proximity.
A good custom integrator will be faster, do it better/more reliably and if you need to change cable types later, you shouldn't have a problem
as long as they run smurf tube or conduit. It may cost a little more but it will work out better in the long run.