This thread has a ton of feedback on that, including specific results with PS4 + SSD + MLB The Show 2014.
http://www.dayonepatch.com/index.php?/topic/106571-anyone-put-an-ssd-in-their-ps4/
Looks like the difference was substantial for that title.
Hybrids are not that great TBH, there's nothing about them that really benefits much over a standard hard drive. Some of the comparisons I've seen between stock HDD and Hybrid HDD/SSD drives forget to account that the stock drives are 5400RPM, and many of the hybrids they're looking at also have 7200RPM drives.
IOW : a 1TB 7200RPM HDD vs. a 1TB + 8GB Hybrid HDD will perform virtually identically in most respects (as 8GB is almost nothing, and there's not a lot of cross-loading going on with small library files as in Windows). Even in Windows PCs, if the most-used stuff isn't being stored in the SSD cache, or if the PC has so much ram that it seldom hits the HDD for general OS activity, once again hybrid drives don't do much.
I just feel it's somewhat misleading to even call them 'SSD' in any major way. They're just standard hard drives with a teeeeeeeeny tiiiiiiiiny SSD cache on them. Eg : in your case 500GB Samsung Evo with 500GB of SSD space, all of it deadly fast, vs 500GB Hybrid Drive with 8GB of SSD space. 500 vs 8.
But yeah that price. SSD have come down a ton, but 500GB will still set you back. Up to you if you think it's worth it.