[JohnRPollard]

The stand up blocks in the first photo would probably be okay. They worry me a bit when they get real heavily loaded, but on a boat your size it's not a huge issue.

My preference would be for the genoa lead blocks in the second photo, for the good reasons Faster mentioned.

We have both the genoa lead blocks on our track, as well as the stand-up blocks. The stand up blocks are at the aft end and are used for the spin sheets (our track is outboard on the cap rail and is VERY long).