In reply to Wooj:
I got a Petzl adjust after 30 years of sport climbing without one.
I really like it, and it's permanently on my harness when I'm on a sports climbing trip. Unlike others, I don't feel that its obstructive or heavy compared to carrying a rack of draws.
If anything I'd say it's more useful for newbies than for more experienced climbers.
- Having a screwgate fastened into the anchor feels much more secure than an extra quick draw
- The lanyard gives you more flexibility about your position for threading, sometimes a real advantage if the anchor is awkwardly placed
- I also suspect that there's less potential for newbies making fatal mistakes when threading such as accidentally knocking the weight-bearing quickdraw open.
Agree with everyone about how awkward the original one is to extend - for me it's become second nature to extend it fully before setting off.