Do the math.
A hybred HDD (ie seagate has a 750 Gig drive with a internal 8 gig SLC SSD About $150) will only speed up what is in the cache. Generally most of the performance whould come from the OS load, For programs and Games load time is a gamble as you are limited to 8 Gigs.
With say a 120/128 gig SSD, everting on the SSD is speeded up. However it is more expensive as the SSD will be around 100 bucks plus the cost of the HDD, around $200 - About $50 more than Hybred with limited caching.
For desktops, and with performance as an objective, go with a seperate SSD for OS + programs and a HDD for storage. The Seagate hybred would be a good choice for a laptop that only has a single drive bay - reason, might want more that the 128 gigs space.
Typical Windows 7 OS + programs is around 30 gigs, add to that games you would install. You figure, 8 gigs in cache speed up, or the 30 gigs + games speed up - YOUR Choice.