It has been reported before, and was mentioned in the latest update that VBOs can be used to improve FPS/speed of the game, and snapshots, also that there were attempts to address the apparent lag that was occuring with the screenshots.

It still seems there is an increased amount of lag in the screenshot (14w29b) I was trying to test if a possible texture bug was still in effect in the latest snapshot, and the world I had created originally on the 1.7.10 version, had a lot more lag than before, and was causing severe framrate drops, even with VBOs on.

The latest changes that were made seem to have not addressed the apparent lag.