I have watched every season, and it is down to enjoying the tattoo art process, which is about one third of the show. After the first couple of seasons, it was pretty clear that winning artists are pre-chosen for the final round, and they are going to win no matter how awful their tattoo is on any specific week.
The final episode used to be two hours of these characters just trash talking, and it was impossible to watch. Even at one hour, the final episode every season is the worst one. The giant back tattoos are usually not that good. Whoever made the best full back tattoo never wins. It is by far a rigged competition.
Every season, there are at least two men who are real jerks, and one or two women who are very arrogant and snotty. The rest of the artists in the competition spend their spare time either hating each other, or arguing. The fighting every week makes up about one third of every episode.
The Flash Challenge is some random contest where the competing artists do some totally useless activity, like making houses out of popsicle sticks. This big waste of time takes up the first one third of every episode. Most of the time, if you start watching after 30 minutes, you have not missed much. The best way to watch this show is to view it one week after every episode, and then you can fast forward through all the garbage time, like the flash challenges.
The three judges have very little personality. Dave Navarro used to be a guitarist on Jane's Addiction. He often does not give his opinion at all. He is not a tattoo artist, so the only reason he is on this show is because he is the closest thing to a "celebrity" that they could get. The other two judges are tattoo artists nobody ever heard of, but they claim to be famous.