Hard to get a general idea, as reports are all over the place. Few will come on a forum and post that they just finished a long road trip and everything went well, but if someone has an issue, this is the place they will come to vent.
Model X is the most complicated vehicle Tesla makes. It is aluminum intensive in frame and body. It has the largest glass windshield and panels, it tows the most (5,000 lbs) weighs the most. Has the most sophisticated adaptable air suspension and computerized anti-sway for trailers. The Falcon Wing doors are perhaps the most complex in the industry. It has the largest choices of seating configurations and is produced in relatively limited quantities. Considering all this it is amazing that it does not have even more issues that we see reported.
Tesla has a "no chit chat" policy. It is difficult to get someone on the phone to talk out your issues. Mostly you need to file a service request and wait for them to get back to you. They will either make a service appointment, send out a mobile Ranger, do some remote diagnostics or repairs via OTA system. Many have reported that Tesla has done even more services than they brought the car in. If the computer indicated something needs addressing they will attend to it when your car is in their shop. Sometimes they will tell you it is a known issue and there is not a current solution, or even sometimes go totally radio silence, leaving you fuming.
Many have posted that their service centers are totally amazing. That they got everthing fixed on the first go, and gave them a great Tesla loaner while in the shop. Others get Uber credits, say parts are back ordered or suggest you phone a friend to come pick you up.
With so many reports, all over the place it is a challenge to get a general idea. More often it comes down to specifically what your issue is and the luck of the draw.
Easy going people tend to be pretty happy with their services, but picky people or those with very high expectations often feel put out.