Not happy with the performance of a SSHD in my PC. Using it as a Steam drive was terrible - GTA V took forever to load.
So I tried moving OS X over to it and using it for that, as I always think OS X works best when it has a single big drive, but the boot times were awful. Once you're in the OS it's pretty okay, but nothing compared to a plain SSD.
So I swapped around and now I'm back to basically where I started, except Windows now has it's own SSD:
I'm considering moving over all the stuff on my Green over to the SSHD and using it instead, as it is a bit quieter, and then making the Green drive for backups, maybe partitioning it 500 GB for HFS+/Time Machine, and 500 GB exFAT for Crashplan.
Using a SSHD just isn't fast enough for me on my PC. It doesn't act well as a Steam drive, or as a OS drive.
On PS4 you're likely to switch games less frequently, because you are too lazy to change discs (unless you buy digital but then you have other problems). This allows the 8 GB SSD cache to fill up with the game you are currently playing a lot.
For a game like Bloodborne a SSHD makes a difference. It can cache Hunter's Dream (the hub) and the current area you are in. If you play Destiny, it can cache the Tower and the current planet you're roaming around on.
The PS4 OS gets accessed frequently and will always be stored in the cache.
On a PC I didn't notice any difference between a regular HDD and a SSHD. On PS4 I have noticed the difference. A death in Bloodborne is a lot more time consuming now.
Anyway, that's it. Don't buy a SSHD unless it's for your PS4, or maybe other game console where you can swap HDD.