There are pretty widely varying opinions on this and I myself have been back and forth and don't know where I currently stand. I highly recommend spending some time in the GH thread. Its an amazing little device, but its a bit of a "project" in my opinion and doesn't provide as solid of a vaping experience next to the FF2 and Crafty. I'd say, like the FF2, its controversial and, for me, it's tough to recommend it without a strong emphasis on "do your homework!"
People don't tend to get very excited about S&B devices around here, but they are all powerhouses. Some things have been improved over time. Their devices do kind of "just work" almost universally. They are kind of like medical devices. Very well designed, tested and functional, but a little sterile and lacking character. If you want a vape that speaks to your soul, maybe check out a different brand, haha.
I think a lot of people assume at some point you will have to service your Crafty. The frequency probably depends on how you care for the device and how you use it. Maybe plan for around $70/year of maintenance on the crafty and a little while without it, but between services, it should rock your world. No guarantees, yours may run carefree for years, but if this possibility is a show stopper, its worth considering other options (haze v3? vapcap?).
The FF2 is an unknown for long-term durability, but it does have swappable batts, which will help.
The GH is pretty well known for not being durable or reliable at all. It 100% requires a backup vape, if you are at all concerned about being vape-less. They do have a lifetime warranty and may very well work out the bugs.
I have not yet had any reliability issues with either of my two GHs, my Crafty or my FF2, but they are all very new and I'm not pushing them hard.
I'd suggest that if you want to go deeper on comparing some specific vapes that you start an ask FC thread after you've narrowed it down to a few devices and your primary concerns.