Been using it forever. Sometimes it's unreliable, but nothing that can't be fixed by restarting it in the system tray.

Important is to either build your own profiles for airports or download them from Flightsim.to. 

It can be used as is, but it's highly customizable and for it to really shine it needs to be tailored to each scenery by hand.

I feel like GSX is better if you have a standard set of airports you fly out of. Then you can do all the work of downloading / setting up profiles, customizing gate stands and all that. 
 

but if you are constantly going to new airports.. it is not as much fun. Though of course the pushback and stuff generally works. 
 

I used GSx a lot in p3d, and was disappointed with the MSFS version as well as the customer “support” (which basically boils down to blaming the customer for everything and claiming everything is perfect with the program). 
 

but again, some people swear by it so I assume it works great sometimes in some circumstances. 

17 hours ago, JonathanC said:

I used GSx a lot in p3d, and was disappointed with the MSFS version

I saw last night what did I miss from the P3D version: I have GSX L2, which includes SODE jetways in all airports that used the default jetway. That allowed GSX to give me a consistent experience everywhere. In MSFS it's a constant hit or miss.

I understand this is an Asobo issue, not an FSDT one. Unfortunately, I think sometimes about other options.