(FWIW, the first month or two academically are all review here, and particularly boring/painful for kids who don't need review/repetition...so no great loss, in my opinion.)
Given #s 1 and 2: Grade skip must be looking pretty good right now...
I'll be curious to hear what you decide, and best of luck!
The first two months are always review, even in elementary level. By the end of the first week, after the assessments are done, our DS got really really bored

So I agree, acceleration seems to be a better option. In this case, if he's accelerated, since they will be reviewing 6th grade material in the first 2 months, hopefully he won't get too bored
We spoke with our Principal and lent him our Iowa Acceleration Scale. It looks like the shadowing will happen very soon... We'll see what happens.