How can I play downloaded games on PS3 Firmware 3.70+?

Hi guys
I haven’t bought a PS3 yet – but i’m about to. It’s a PS3 Slim, and I’m guessing the firmware is newer than 3.55 – probably 3.70.
I’ve been searching for an awnser all night, but there are so many different awnsers. I can’t figure it out..
Is it possible to, somehow, play downloaded games on a PS3 with firmware 3.70? Or downgrade to 3.55?
Answer #1
no probably not
Answer #2
That sucks
Answer #3
http://ps3.dashhacks.com/node/1936
Answer #4
i would say no. Only advice is buy a older ps3 off ebay