My family has flip-flopped between the two. Went from Cressidas to Maximas and Quests to LS430s and Sequoias to G37s and M37s and Frontiers to now Tacomas and GX460s and GS350s. For me, I think it's more about the individual car. We'll see how the 400Zs end up being in the long run as the VQ/VR...
My friends mostly run the SCXs, and they're super capable. A little smaller, a little less scale looking, but huge aftermarket. The axles on them are worm gear drive, so they don't coast like regular geared trucks, but it means it has a huge amount of control. The TRXs just look better though...
We've really been enjoying bringing out the R/C trucks on our trips - each person will bring one or two TRX-4Ms or SCX-24s and we'll build a rock course.
I also have far too many R/C cars. Two 1/16 Traxxas (E-Revo and Slash), an ARRMA basher thing I got for cheap, two 1/28 Kyosho Mini-Z 4x4...
I'm glad it's working out well - there's a lot of comments online about the longevity of these (all anecdotal) but doesn't seem like the actual owners have any issues. I'm still waffling between this and a separate carrier, as I agree that having a separate unit you need to unlatch is annoying...
Bit pricy, but they make Defender 90 bodies in 10th scale. RC4WD makes some of the better ones.
https://store.rc4wd.com/rc4wd-2015-land-rover-defender-d90-body-set.html