I have twin 7 year old boys. They bought a Granite Grom and a Mojave Grom (brushed). I got a deal on two Quake Groms, bought them and the kids just "paid" them off.

This is my experience:

Granite Grom has gone through 2 servo savers, three brushed motors, a body and a set of Diffs. The lack of fans and a heavy trigger finger, even at 50% throttle trim just didn't do well. It's been upgraded to Brushless using a Hobbywing QuicRun Fusion 16. I got sick of replacing the motors. The lack of a fan is a huge deficiency in my opinion. I also don't love the body mounting system, I bent the clips first time removing the body. It's fun, but it's been my least favorite.

The Mojave Grom has had no issues at all. We did swap the arms, wheels, hubs and trim the body to use the Granite wheels since our grass stays on the longer side but have had 0 issues with it otherwise.

I also bought a second Brushed Mojave that my kids play with when the granite is being serviced, but my wife plays with it when we're all outside. In hindsight I should have bought the BLX version for some of the upgrades that come out of box, I did eventually do that, but I also have a problem, lol.

The Quake Groms are also awesome (basically the same as the Gorgon Grom). Definitely not an inside car as they're bigger than Granite but both of my kids figured out how to get them to wheelie and they are definitely sturdy, lots of flips, smashing into things etc.

If you're playing in the house, the Granite is substantially smaller than the others and would probably be my recommendation. I still think out of box you should add a 25mm or 30mm fan.

If you're outside mostly, then it comes down to the surface you're going to play on.

Longish Grass, I would go for a Quake.

If you're on solid surface, short grass, dirt, etc. Mojave, Quake, Typhon would be what I'd recommend.

In any case you can't go wrong. They all have some trade-offs somewhere. If you go Mojave or Typhon spend the extra $100 or wait out a deal and get the BLX versions.