A GFC is far superior to a RTT mounted to a rack or shell.
I had an overland-style rack (self-designed and built by a friend) and CVT Mt. Shasta RTT for four years mounted to a 1st gen Tacoma. The rack stayed on year-round and the RTT went on for summer & fall. I used the RTT 12-30x per year (probably a little less than 100 nights in total).
My old 1st Gen with the overland rack/RTT setup
I originally thought that the GFC was a great design but that I was all set with my rack & RTT setup. The flexibility of removing the tent seemed like a big upside to me compared to running a GFC full time on the bed. I also considered going with a GFC RTT in place of the CVT soft tent, but that didn’t seem like much of an upgrade for the cost. I use my truck as a truck quite a bit, so my basic requirements were to carry: (1) 12’ lumber, (2) Full 4’x8’ sheet goods, (3) A bed full of firewood. The rack allowed for this in spades (but I did have to remove the RTT for lumber & sheet goods).
The primary problem I ran into with the rack was security of tools & gear. Living in a more rural or suburban area made the risks much smaller in the short-term, but doing something like a road trip presented much more difficult problem to solve. The GFC provides far better shelter from prying eyes and the elements, so I changed my mind and put down a deposit on a (then) V1 in Jan 2020.
I finally picked it up in April 2021 and spent almost a month sleeping in it during a road trip around MT, UT, & CO. After returning home to the Northeast I used it for an additional 30+ nights in 2021 (also on track for a similar number in 2022), so your estimated use (50-100 nights) seems in line with mine. It sounds like a lot, but you’d be surprised how quickly they add up over the course of a season. I have not used it in the winter and don’t really have plans to- winter camping isn’t really my jam.
Current 1st Gen Tacoma with the GFC & awning
Security of Gear/Tools/Stuff
Yes someone could pry open the aluminum sides (or open unlocked tent latches) to gain access, but the same could be said about the rear hatch of a shell (nevermind just breaking the windows). Out of sight & out of mind has proven to be the most effective deterrent for the vast majority of would-be thieves, and the solid aluminum panels on a GFC definitely provide that. It’s also why I think rear windows are a bad idea on a GFC unless someone is really going to use the space for long-term camping & living.
Protection from Weather/Elements
Obviously covering everything in the bed adds significant protection from the outside elements compared to an open bed. A shell would also provide this, however…
Access to the Truck Bed
This one is HUGE and also the primary reason I dislike shells on trucks. Unless you have flip-up side windows (and most shells I’ve seen in the wild don’t), the front 2’ of a truck bed becomes dead space or deep storage when using a shell. I loved my rack because it didn’t cut off access to the front of the bed. Because the GFC is essentially a frame with flappy panel sides, it performs quite similarly to my rack in terms of bed access.
Access to Truck Bed from Tent
This benefit became very clear the first time I got dressed standing in my GFC with a couple panels removed. It became even more abundantly clear the first time I packed up the truck during a downpour and was able to get dressed, make coffee, & put everything away before going out to pack up the tent.
Ease of Setup
I thought ground tents were easy to set up. Then I thought my CVT RTT was easy to set up. Now I’m spoiled with the GFC- <10 seconds to bed. The ease of setup also leads to a higher use rate (for me, anyways). I frequently encounter the question, “Do I leave and drive home or stay at my friend’s house and have a couple more beers?” Always nice to have the option to stay longer and avoid driving home.
The higher use rate also means the cost/use has approached that of the rack/RTT combination much more quickly than I anticipated. Just with a few rough calculations and estimates, I’ve come out with a “cost/night” number for the GFC after 2 years that’s close to the number for the rack/RTT setup after four. I’m not going to type that all out here, but suffice to say that I’d still be happy with the GFC even with a longer cost/night equalization.
Truck Footprint Remains Unchanged
A softshell RTT folds out in a direction and takes up an adjacent space. A GFC or hardshell RTT pops up and does not increase the vehicle’s footprint. Arguably not a huge deal, but in practice it ends up making parking site selection easier for the latter rig in many places. The space underneath a softshell RTT is nice, but rendered moot by the ability to go between the truck bed and GFC tent (and/or the addition of an awning).
I have a very small truck. Granted it does have significantly more torque with the diesel engine swap compared to the factory gas motor, but weight still matters. I think I’d be hard-pressed to find a similarly-featured setup in such a light package.
Somewhat offset by the aforementioned quick cost/use equalization compared to rack/RTT setup, but $7000-8000 is still a significant commitment for most people, myself included.
Semi-Permanence of Installation
The GFC is definitely not intended to be donned & doffed like a shell, RTT, or rack.
You’ve got to drive to Belgrade or pay an arm/leg/left nut to have it delivered & installed in your area. I don’t think shipping costs are overcharged- just that the cost of freight is what it is.
There are probably plenty of other downsides that others can bring up; I can’t think of them now.
Good luck with the decision process.