The Zeiss QC may be no worse than Leica's, unfortunately. But, the dealer/manufacturer response is probably better than Leica....
I just paid $2000+ for a new 50mm Leica Summilux-ASPH. Tested it against the ZM50, 50DR, Jupiter-3, and Canon EF50/1.4, as soon as i got it. Found out i had received a lemon. The ASPH was clearly and significantly soft.
I sent the lens to Leica New Jersey, and a week later they inform me it'll take 8-9 weeks to have it fixed/replaced. TWO MONTHS. Meanwhile, someone else still has my two grand....
I just sold the DR 50, but luckily i still have the Zeiss. Congratulations on getting yours. You're going to like it.