I was familliar with the KSM9 microphone and while searching for a wireless upgrade I came across the ULXD. I was able to rent the ULXD24/KSM9 twice for a couple of live performances in medium venues (up to 400 people). It was amazing in every term so I decided to buy my own. And then I descovered the QLXD offering the same sound quolity, the sane level of building quolity having almost the same specifications but in a lower price point (as it's missing some very minor - for my perpuses - specs).
I was a bit sceptical in the beginning but then I decided to go for it and, today (more than 3 months using it), I have not regreted it! It worths every penny!
The only downside (as in most wireless systems) is the battery life, as the 2 AAs will not run it for more than 1,5 shows for me, so I will go soon for the rechargable battery that Shure provides for these series.