i cant really speak to much about build quality the UE line of earphones has seemed pretty sweet to me, the super fi 5 pro cable was a bit scruffy and thin and the triple fi 10 cable hasnt been the most reliable or comfortable but the earphones themselves are all good ( dont know about lower end models ).
in regards to logitech taking over i dont think they are anywhere near as friendly as the old team, i havnt received a reply off them in a long time, ive asked numerous questions about the technology and help with stuff to do with the earphones but have not had one single reply, i bet if i was putting an order in tho id be the first to get a reply, does that sound like great customer service to you?
in contrast shures customer service is some of the best ive ever had the pleasure of dealing with, i have since sold my se530 and moved onto some cheaper (here in UK anyway) sennheiser IE8, brilliant headphones for me but you know what i havnt heard much off them either, peace.