I upgraded my exhaust a few months ago after quite a bit of research. Here's my take on how that upgrade has gone and my criteria in the decision process.
Tacoma
When I had my Tacoma, I watched dozens of YouTube videos, trying to determine which exhaust would be best for the truck. At the time, I wanted something with a different sound, but didn’t want something too loud.
I remember trying an AFE intake on the Taco and hating it. It was embarrassingly loud and vibrated the floorboard. Ultimately, I went with the TRD intake and TRD exhaust. It wasn’t too loud and had the sound I was going for, and there were noticeable performance gains from the exhaust.
Gladiator
Now with the Gladiator, I’ve been totally fine with the stock setup. Maybe it’s because I’m getting older, but I prefer a quieter ride, and regardless of my age, I don’t want to drive a V6 truck that sounds like it came right out of a Fast and Furious movie.
So, why swap the exhaust? The answer is that the tailpipe’s resonator hangs super low, and with a high clearance bumper, it was just kind of going to be... hanging there. Kind of weird to aim for high clearance and then just leave some parts hanging below the bumper.
Once again, I watched dozens of videos and determined that the best mix of sound and volume was the AFE Mach Force-XP 3” Hi-Tuck. The Rock Basher and others were on my list at various points, but I didn’t like the sound (again, Fast and Furiousy), plus they seemed really loud. I was looking for similar volume, maybe a little more growl, and most importantly, a tailpipe that’s out of the way.
Here's a clip of the exhaust sound. Note that this isn't a cold start, which seems pretty typical for videos on YouTube.
AFE Mach Force-XP 3” Hi-Tuck
This is absolutely the loudest I would ever want my exhaust to be. I sounds great at low RPMs and it gets a bit loud past 3,500-4,000, but it’s still acceptable. The sound is great, and I think it’s encouraging a softer touch on the gas pedal, so I suppose that’s nice.
I’m not finding that it drones on the highway, but consider that hearing stuff isn't exactly easy when driving this truck :-). I will say that living in a mountainous area, there are plenty of climbs where it’s sitting in 4th running at 4-5k for long stretches and you get that “whooom” or “airplane take-off” sound for that duration.
My suggestion is simply that if you need some more clearance but want a quieter exhaust, this is, in my opinion, the best option. But if you can, just stick with your stock exhaust. All vehicles will be electric (silent) one of these days anyway.
UPDATE: I ended up removing the last section of tubing from the exhaust system, so the exhaust now terminates just over the rear axle. I did this because I'll likely be cutting the body soon and even this exhaust was hanging lower than I wanted it. Now it's a tiny bit louder, but otherwise sounds the same and is totally out of the way.