Well yea, it is. Whenever you're actually on a mission you are sure to enjoy some epic moments, and even roaming around is fun, but it just feels boring how much every mission is far away from each other, and how you have to call a cab, wait for it to come, skip the travel, wait for it to load and then go to the mission and read for example *return as Michael to start this mission*, and then the cycle repeats itself.
I liked the sports and all, but after some minutes they start feeling a little bit boring, and when you want to fight some cops you are most likely just going to die, a lot. Most of the side missions feel pointless and nonsensical, such as pursuing a limousine with an annoying paparazzo freak talking shit on the back trying to take photographs, it doesn't seem to fit the personality of the characters. Don't get me wrong tho, it's by far the best GTA game out there, its awesome, but its just not the ultimate definitive greatest gaming experience in the universe, as the hype tried to make me believe (I did, a bit). From the technical point of view, I would give the game an 9.4 out of 10, it is really well structured and could easily rise up to a 10 with some minor patches, because I had problems with stuff that was important to the mission becoming invisible and such. For the overall story and experience, I would give it around 8.8 out of 10.