It had many more CXMB themes than 6.60 as of last time I checked on Wololo's talk forums.I don't disagree but just saying new games in 2012 still work on 6.20 CFW so I don't find I need to update it or rather I don't know how to and 6.20 has better CXMB themes ?Yeah I guess, but I generally rather install the higher firmware, but if you want CXMB themes then 6.20 is the better firmware for themes.Oh then sure thats cool.He has a 100X model, and it's generally better to have the newer firmware installed.Why 6.60?Flash to 6.60
Install the PRO-B10 CFW (Many guides for that around the internet,Make sure you install the custom ipl too!)
Everything should work fine.
Unless he uses a 100X/200X model then that suggestion wouldn't really help plus I don't think there is much difference between 6.60 and 6.20 CFW for the PRO series cause they both play games that require higher FW in the first place and both plays homebrew fine.
Well thats a little subjective I mean I use 6.20 and all the games that need higher FW still run perfectly with no problems so I don't see the need to update it to 6.60.