I have 2 Jeeps currently with the 6 speed, and 05 TJ and 08 JK. Just had the TJ rebuilt. It shifts like a work truck to some degree, and I don't mind, no grinding but it feels mechanical. The 08 is like butter, weird how different they are, weird.
Driving wise, I am in town a lot, 45 to 55 mph type roads with decent stretches between lights. I'm rarely if ever in 6th. I drive 1-5. If I am moving at all, tires rolling even minimally, I go from 2nd on both Jeeps, 33's on the TJ and 35's on the JK.
Hill Country rock climbing, wheeling etc, 6 speed 1st gear is like having 4 Lo when you're in 4 Hi. I like that, personally, it's super torquey, just rolls and climbs things, excellent. 4 Lo, 1st gear is for emergency wheeling, its crazy torque, which can be useful, I have less than a handful of times needed.
On the highway, I do between 70-75 and it's the only time I'm in 6th, and they both cruise no issues, where they should be. Lots of vocal folks love the 5 speed and hate the 6, free country and their opinions are valid. I have no problem with my two 6 speeds, shifting isn't a bother to me, I actually like driving, then again I had a CJ5 V8 3 speed and drove an hour in Houston traffic both ways for about a year, and just considered it fun.