Seed #6 has always been the tallest. While under the grow lights, it's really grown significantly, now working on its first branches.
When transplanting from a cel-pack, it's important to (carefully) use a razor to cut the plastic away from the root ball. These little plants are still so delicate. If you disturb the soil, it could tear the thin root hairs - if you're lucky enough as to not snap the stem first. When cutting, you need to remember that there may be roots up against the plastic, so try to keep the razor from slicing into the soil. You're probably going to lose a few root ends, but it's better than killing the seedling all together.