Recommend the 60 Gig vortex-2 or Intel 80 gig G2. The intel G2, lower performance, higher cost, get 20 gigs more space
The two OCZ SSDs are the same size. The difference is in the "hidden" gigs that the SSD uses to do it's "garbage collection" The 50 gig was first, and the 60 gigs was 2nd - they found that the 50 gig version was slightly faster, but the extra 10 gigs for the user was of greater "value" - more than offset the slight performance diff.
On a day-to-day usage (after the computer is up and runing and you have loaded your programs), probably would not see much diff between the Vortex and the Intel. Boot time and program loads would favor the Vortex-2.