On my Intel Core i7-4770, VanitySearch runs ~4 times faster than vanitygen64. (1.32 Mkey/s -> 5.27  MK/s)
On my  GeForce GTX 645, VanitySearch runs ~1.5 times faster than oclvanitygen. (9.26 Mkey/s -> 14.548 MK/s)
If you want to compare VanitySearch and Vanitygen result, use the -u option for searching uncompressed address.
VanitySearch may not compute a good gridsize for your GPU, so make several tries using -g options in order to find best performances.
Using compressed addresses is roughly 20% faster.