We do not regard grade skip, and although we do not have any bad experiences, I cannot say that it did much for our ds. I do regard that we did not do one right away in K and then we still could have done another in 2nd or 3rd grade. However, not sure what difference it would have made. We waited because we had zero support from school; at end we did the grade skip anyway. My ds skipped 3rd grade and none of the problems that school predicted and warned us about materialized. 4th grade was a good fit for him socially. Academically very early on we realized that he was not challenged enough anyway. When we started to talk to him about skipping 5th grade, he was against and we did not pursue it. Now he is in the 6th grade, taking 7th grade math, but really brings easy As in all subjects. Fortunately his science teacher has noticed ds abilities and has told us that he will do everything he can to keep him challenged, will challenge his thinking, will make sure that he thinks about each topic more critically and in general will have higher expectations of our ds. But that is only one teacher! I am slowly working with the school system and by the time he is in 8th grade, he will be taking mostly high school classes.
Ds has only one friend that they spend all time together and lucky are taking the same classes together as well. Sometimes I worry that he is not making more friends at school. I have talked to him about this, but it seems this does not bother him. He has good friends outside school setting, one in our neighborhood and then several from his soccer team and other sports activities he is involved.