The GX is a LOT MORE Car. That said, it has its quirks. One thing that people don't seem to appreciate. The gX makes its power at about 1000 rpm lower than the 4R does. that makes for a much better driver. You just don't have your foot in it as much and the extra gear just adds icing to the cake. The rear door is strange, and takes some getting used to. I have not found it to be an issue, but would prefer the lift gate, or split tail gate. The higher roof line is really nice,even if your not tall. The 4R seats in the back lie flat more like the Jeep Cherokee, that's really nice compared to the gX middle row. But the third row folding into the floor is much better. Break over angles suck, and its ugly.
I get better gas mileage than reported by my 4R friends report. I drive with a light foot, and the extra torque at lower RPM lends to better fuel mileage. The suspension setting are worthless. My guess on the sound system is.....It sounds great until you turn it up. I think it lacks amps to drive the speakers at higher volume.
Over all, I'm really glad we bough the GX in stead of the 4R. It's so much more car. And we would have bought the Limited 4R and it really sucks in many ways that the TRD is great in, but the TRD lacks in the areas the GX shines in. So best in all worlds. This comes to mind. The part time T-case in the TRD and some (I don't know if all) Limiteds can't lock up the Torsen like the gX can. That's a big deal for us. Good luck on your choice. I think a new GX goes down in value quicker than a 4R because many people don't understand what they have.