Way out of date 4.46 PS3, want to get up to speed.

I have a dusty PS3 on Rogero/Cobra 4.46 on a backwards compatible ps3.

I dabbled with Webman and all the Jazz with some Ps1/Ps2/PSP backups. but I only really had luck with PS1 and PS2.

At the time, Habib's 4.55 was a sketchy firmware because PS2 didnt work natively like it did with the Rogero CFW. is this all in the past? Am I totally good to go if I just install Rebug 4.75.3 REX ? or will I be losing any functionality?

Downgrading CFW is kind of a pain in the ass so want to make sure I do it right.

thanks!