For safety go back to 3.55 OFW through the recovery. In my opinion rogero 4.30 is the more active 4.30 CFW but there are others. Read carefully don't skip steps. If you are unsure don't risk it and do research and ask.
Going back to 3.55 OFW doesn't make this more safe, upgrading through recovery doesn't either. People say It's safer but so far nobody been capable of explaining why. There was actually a thread about this on other scene site and we kinda came to the conclusion that recovery doesn't avoid bricks.
I'm highly against people going for 3.55+ without flasher due to RSOD. If you RSOD on 3.55, you can easily fix It by software, but if you get that damn screen on 3.55+ you're stuck and will have to get a flasher. That's just not worth It, specially because 3.55 Kmeaw can do pretty much anything 4.30 Rogero does. If you insist on upgrading your CFW, 3.55.3 Rebug then? It has some nice features, you most likely won't use most of it though.
Use EBOOT fixes? There are fixes for pretty much everything. I know that can be annoying but RSOD isn't as rare as you'd want it to be and it's just not worth to have your PS3 there with a random chance of making you waste a hundred dollars.
I suggest upgrading to REBUG REX 4.21.1, so far so good, with so many features you'll like. i'm playing online too except for COD's, & my friend told me there is new REBUG 4.30 CFW coming out this xmas, he's a vet & he knows one of the REBUG developers, so i can't wait for that too, thats what he told me, don't shoot the messenger.