Hmm... I've had my Custom 50 for a couple years now... fantastic amp! Takes pedals like a gem, in fact I use it for a clean platform in a lot of cases.
What I've found in regard to speakers has been mixed. The amp isn't overly bright, also certainly not lacking midrange, so with V30's, it really depends on what you want to do. Lead tones with the right pedal or gain channel in the amp are righteous with lots of mid cut and not piercing, which is where the amp really shines with V30's. Rhythm tones are also good if you want that honky cut. On the flip side, the amp can be so mid focused with V30's that the tone doesn't have much chime or bite without really maxing out the presence, bright switch, etc.,and too mushy on the bottom for punchy rock and blues riffs. It really accentuates that "mid honk" that people talk about with V30's.
I have an older "SE" 2x12 with some OEM Eminence speakers made to PRS spec, more aggressive highs and lows and less mid than the V30's, and I would say they're a better all-around speaker for the amp, if you play more modern music - although there are times I miss the mid cut of the V30's. I don't know what to say they're like from experience, but I by speaker descriptions, probably somewhere in the neighborhood of Lead 80 or G12t-75, which PRS is using now, I suspect due to the same reasons I went for something with different character. The V type speakers may also be a very cool match for this amp.
Someone mentioned in another thread recently that the Archon can change its character nicely with different speakers, and I would say the same about the C50. A nice neutral (in a good way) sound that can do a lot of things depending on what else is in the chain with it.
