He's a fun guy to have TA physics lab, but more work that other TAs. He lectures at the beginning of lab enough that the only prep work you need is to read through the lab once for 5 minutes. He's really into physics and excited about it. He will make sure you do that whole lab, though (other TAs sometimes let groups skip sections of the lab). He understands what's going on- so your experiments will work. You'll stay later at lab working than you will for other TAs, and he's more anal about the labs (and not that easy a grader, either). I think Prof Dodd (who runs the physics lab) knows this, and thus gives people in Jamie's lab higher grades than they've earned.
Basically, you work a lot harder for this lab but you'll get graded on an easier curve. I'd probably recommend another TA (for a lower workload) but if you end up with this guy it'll be okay in the end.