"It's warm," I said of my blood at one point. "Proof I'm not a vampire!"
We didn't start the draw as quickly as hoped; the tech first had trouble finding the proper vein on my left arm, to the point that she asked to check out my right arm as well. "Hmm, about the same," she said, so I made sure to squeeze more vigorously with my left hand to get my left arm's veins pumping a little more strongly so she could find it.
It was worth it. How worth it? The draw, normally a 10-minute process, took me 6 1/2 minutes. She said "Your vein was small, but it was strong once it started flowing."
So it's not the size of my vein that's important, it's how well I use it.