I have both of my Radians installed with SL and I'm not concerned. If the SL doesn't work/isn't compataible in a specific car, then the seatbelt should definitely be used instead for the install.. But I wouldn't make the general statement that SL shouldn't be used in any cars.
The problem is that it's not easy for the average consumer to see whether it's compatible, unless you know exactly what to look for. It can seem tight at the time of installation but loosen over time.
Yes, this. I have to disagree, and say that I have told my daycare parents (two of whom have gotten Radians recently) to not use the LATCH straps. It's too much to ask them to keep tabs on it.
A couple of months ago, I installed my RN with SL. I was well-aware of the problems, so I examined it very carefully -- pushed, pulled, checked that the LATCH strap didn't fall at the edge of the belt path, etc. I felt very comfortable with that install, and checked it for tightness several more times that day before declaring it compatable.
Two days later, I went to take the seat out -- reached around the side and darned if the tilt-lock mechanism wasn't hanging out an inch away from where I'd left it. I don't know how or why it loosened, since there was no apparent incompatability, but it was enough to know that I will NEVER install with the SL strap again, in my car or any other. It doesn't mean I don't recommend the Radian, but I make sure it's seatbelt-compatable, and that's how I help to install it.
I consider myself a bit more saavy than the average consumer, as well as well-studied in this problem, and it STILL happened to me. I think part of the issue is that nobody knows WHY this happens in some instances, so it's impossible to know what to watch out for.
Anyways, to get back to the thread at hand, I filed with NHTSA but not BBB... I never contacted SK asking for a resolution, so in my case the point is moot.