In theory, a properly done reman using the OE components should be the best option vs a new made in China unit using questionable parts. Problem is, even the reman business is a race to the bottom as the alternator only needs to last the warranty period. Their primary business is turning these units back ASAP in bulk for repair shops, not necessarily the walk in customer who is likely a DIYer and more demanding.
You really have no idea what kind of parts they are putting in there since OEM components are expensive and it may not make sense for a small shop to try and source, special order, and stock those OE components for every single one off alternator. Especially when customers demand a quick turnaround. Much easier using cheapo generics that fit multiple applications. For example, I doubt any shop would use an OE regulator or diode. The result in that is you may get more ripple current through your electrical system. The value in a small shop is you can talk to the guy building it to figure out what he's putting in there and he's likely more experienced than the guys a big corporation may hire in an assembly line.
IMO the best reman should the manufacturer specific one. Eg if you have a Ford then a Motorcraft reman. Generic rebuilders like Cardone in theory should have their processes in place to maintain more consistency/QC than a small shop but the problem is they have some minimum wage guy who doesn't care putting things together.
