Hi Larzza, sorry to hear you got a faulty unit, that's very disappointing. I must say, the amount required for sending it back is very high, is there no cheaper way?
Whether it's worth sending back is your decision of course, Unless you attracht bad luck though, chances are small you would get a second faulty unit. You won't find a better DAC for ...
Maybe the seller will send you a new unit after you can prove you sent the old one back; this way you won't have to wait so long.
For me, Í'm enjoying the FP alot. Unless it has quality-issues and will explode after a months use, it was a great investment. I think it sounds very good.
But, to be honest, I like the DAC-part better then the head-amp-part, which gives a fine sound btw, but on my Senn's it's just a little bit too 'thin', and I prefer listening through the amp of my receiver.
Anyway, you have been unlucky, hopefully your luck will change.