I have never tried a hybrid drive, but it feels like it would do too much work in the background to see a true gain IMO. Plus arent hybrid drives straight up like a few gigs of flash storage anyway?
I can't wait till we get to the point in where 2TB SSD drives are available and affordable.
Hybrid drives just give me a comfortable middle man. You get a nice speed boost from the flash storage being used for cache, but not as much as a pure SSD Drive, which you're trading off for longer write life. Until Windows decides to handle applications and system files better, I stick with hybrids.
This is one area where Linux makes it real easy. You mount /home to your hard disk drive and the rest of / into the SSD and your system is greased lightning. Adding a few lines to a text file, you're well on your way to absolute minimal writes to your SSD. Separation isn't so easy in Windows, and neither is the configuration (and Windows LOVES to access your hard disk for God-knows-what) so your SSD life won't be as maximized as it should be.
I'm falling into technicalities here, so the SSD outta do. But if you want more in terms of lifetime go hybrid. You lose speed, but still faster than pure HDD.
EDIT: For the record I use them in laptops mostly.