Double post, but doing it to answer VistaBlade's question.
I tried the remote play with my PS3 last night. Now, it is limited right out the gate because not many games are compatible with it. You can find lists online pretty easy. But among those that are compatible are PS1 classics, of which I have four on my PS3 (the
Spyro trilogy and
Gex: Enter the Gecko). But besides that, two that are compatible that I personally care about are
Tokyo Jungle and the
Shadow of the Colossus/Ico HD collection.
I have not tried
Shadow of the Colossus/Ico on remote play, as we're currently loaning our disc to a friend. The download version of SOTC doesn't work either, as I have it installed and tried it. However, it worked GREAT with
Tokyo Jungle and the Spyro games. You can connect via private network if the Vita and PS3 are both connected to the same wireless network. I tried that first and did a survival run in
Tokyo Jungle as my boyfriend was playing
Infamous: Second Son on his PS4 and was using the TV. You can also connect via internet, so I could play my PS3 from my brother's apartment or somewhere. Tried that with
Tokyo Jungle and the first Spyro game. All worked great. The 'connect via internet' mode can take a little longer to establish a connection and be a little less reliable, as the screen occasionally freezes for a second and sometimes the controls don't respond perfectly, but overall, it was a good experience. Really, the worst part of it was setting it up as I misunderstood part of the directions.
Have not tried it with the PS4 yet, as my boyfriend was using it yesterday. I did set up my own account on it with my PSN info, so sometime today, I'll give that a go.