Wow! What a hassle on the P5!!!
Personally, I like Parasound, I have a used 1206 that has performed flawlessly, and I just picked up a used ZCD. Price vs. performance on Parasound is tough to beat, probably only Emotiva is a better bargain in general.
But, your problems on the P5 have me reconsidering just how much of a bargain the Parasounds are. One other nitpick for Parasound is how the Halo amps have XLR connections, but don't have fully differential circuitry.
So, can you please tell me what model of potentiometer is in the P5? Ask the dealer if you don't know, please. Mostly, I want to know because I do some DIY projects and I want to know what model of Alps pot to avoid like the plague!
It also makes me wonder if somehow Parasound got a hold of some cheap Chinese Alps Knockoffs. Wouldn't be the first time something like that happened.
And yes, for the price and the marketing on the P5, you absolutely should expect a flawless product. After 2 failures, I would absolutely discuss with the dealer how we could move away from the P5 and keep me a happy customer (i.e. keep me from spending any more $).