We did not early entrance DD8 and I wish we would have. We did not know she was gifted at the time. She doesn't want to skip now and we've respected that. I've had to do a LOT of advocated at school in her behalf. It's been really hard/draining but I think we are in a good place. We've been lucky to have a great principal.
We didn't early entrance DD5, but this time we had the information that she is highly gifted. She is a summer birthday and her behavior was such that we thought she might stage a kindergarten coup and try to gain control of the principal's office. We figured since Kindergarten was half day, we could see how she does. smile
The psyd. that tested them recommended that both girls should be skipped/accelerated, but we are making it work.
I don't know if things would have worked better if we skipped.
I can't go back in time anymore than you can tell the future! smile
Make the best decision and go with it. Don't worry TOO much about making the "wrong" decision, because you can certainly always change the plan.

Good luck!!

Incog