LOL Sorry...I bought 2 DCs a couple of weeks ago to replace the BVs I sold. I wanted the extra height, and yes, IMO it's worth it! LOL Anywho...I don't have LATCH, so they are installed with seat belts (both ff) and using the built in lock off, as my seat belts, while they lock, do not work sufficiently to hold the seats. After a week or so of having them in, I reinstalled to get a different recline (wanted less), and I discovered that my belts had dents where the lock off was...but more then that...if you held it up to the window, light could actually come through the seat belt where the dent was, from stretching the belt due to the lock off and because of the fact that I put them suckers in SOOOO tight!
Well, I found a solution, I think. I undid the lock off. Tried using the locked seat belt and it wouldn't work. I mean, it works...it just won't go that last click that I need to keep it tight...so there is play, and enough that I likely wouldn't get the 1" or less of movement. So...I tightened it back down, but before closing the lock off, I let go of the shoulder belt and then closed the lock off. By not pulling on the shoulder belt while closing the lock off, it wasn't taught...so it didn't have to stretch the belt in order to close it. It seems to have worked...I'll recheck it in a week or so and see if it stretched it like before.
If it doesn't, I'll forgive Britax!