Re: Does the C8 sound more "modern" compared to CRC-UOA5 and CC?
I think it sounds pretty modern, but with a hint of classic sensibility. The modern-ness comes from the A8's characteristics - tight lows, big beefy low-mids, and smooth highs. The classic-ness comes from the Custom wind itself, which can sound very PAF-y, but has more output than a PAF. Despite the high output of the A8, it still retains a lot of Alnico soul/warmth, so there's that too.
C8 makes a great and surprisingly versatile pickup for hard rock and similar genres. It cleans up nicer than a ceramic Custom, IMO. You can definitely use it for more rockin' forms of blues, but if you're going for authentic PAF tones, then there are other pickups/magnets you might want to use instead.
CC is also good...think overwound, hot, chewy PAF. good for EVH-esque tones.
Haven't tried the custom with UOA5, but blueman says it's a good deal more vintage sounding than the A8.
I think the most PAF-like I've ever heard the Custom wind is with an A4. It's not super high output, and it's not deficient in any part of the EQ, so it's balanced sounding, and gives the wind itself room to breathe instead of slamming it with a high-strength magnetic field like the Ceramic or A8 do. But even with the A4, it's a bit more modern sounding, courtesy of the wind.