When reading the below, remember we are talking about an 8'6" TC with two people. We could add a small dog without much impact, but that is about it. Our camper could be carried on your truck, but not much bigger than it.
Would you ever go back to a tag along?
Our first camper was 30' TT which we used for 8 years. Our second one was a 35' FW which we had for 5 years. While we had the FW, I bought a used TC because the FW was too big to take camping by myself and I couldn't haul the trail jeep behind it. Didn't take long afterward the FW was sold. That was 7 years ago and I'm still running the same 8' TC as it fits just the two of us well.
As we approach retirement, we think about our future camping unit. For the first several years, we will be moving a lot, sitting very little, so the TC will be the ticket. Once we find our favorite areas of the USA and slow down to explore those areas more in-depth, we may switch back to a TT pulled by a Van or Class B. We don't want to loose having the amenities with us all the time and being able to spend a night way off the grid but do want the larger space for when we spend a week or two in one location. Our front running plan is a 30' TT pulled behind our 8' TC.
Rv parks welcome you the same as other RVs?
Never been turned away, but then again 95% of the parks I stay in are government operated. If I ever do find one, I'll just let them know the are a RV racist, tell them my lawyer will be in touch about a discrimination lawsuit and let them sweat bullets for a while. I'll just go on to a better campground.
Is fuel mileage the same or better?
I averaged about 1 mpg worse fuel mileage with a 12k lb FW and my 2400 lb TC. Not enough to let it sway my decision on what I would take along.
Do you use your TC off the truck?
A couple of times when it was in storage at my parents house. I stored it on a utility trailer so the camper was supported. I don't use it in campground for two reason. Foremost is I don't have electric jacks so lowering down low to the ground would be time consuming. Second, because the TC is only about 1/2 the cargo capacity of the truck and the camper stops at the rear bumper of my long bed truck, it's almost identical driving the truck/TC combo as it is the empty truck. In a small TC, it's even more important that everything has it's place and stays in that place. This makes going from parked to traveling a very minimal process, usually less than 1 minute.
What brand you recommend?
They all have the pluses and minus. Lance is most common and has good track record. Artic Fox is well built, great in cold/hot, but heavy. Outfitter good pop-up version.
Any other benefits or disappointments?
Two biggest benefits are I can tow a toy (boat, jeep, etc) and it's easy to maneuver. I never worry about exploring the roads because in the rare event I can't turn around, I can always back up as far as I need. I grew up in a TC so new the advantage. My wife and kids would laugh when I pointed them out while towing the FW. But after getting my wife to take a trip or two, she has fallen in love with the traveling style plus always having everything from commode, to fridge, to bed, to clothes with us all the time.
As far as disappointments, the biggest is it's hard to fit four people in it when the weather isn't great and we are camping with my daughter. But then again, since she has gotten her own camper, it's become a benefit because they have more room.
In your position, I would either be looking at TT or FW or upgrade to a dual wheel 1-ton truck to handle an 11' TC with slides.