I've had a few basses with the licensed MkI stuff in, the pickups are ok and I've always half heartedly defended them on here because they're... well... ok. They aren't an upgrade over pretty much any in house pickup and are there as a cheap way for Cort to slap a high end brand on their spec sheet at a low cost which is something they've always liked doing! If I picked up a bass with MkI pickups in I might keep 'em, I might not.
The MkI preamp is where most people should direct their anger though, hated that thing and if I was looking to improve a Cort/Ibanez with licensed Barts then that's the first thing that would go as the rest is sound. The Markbass pre (licensed again) they're using in some models now is a much better (but still not great) preamp choice IMO, as is the in house Vari-Mid used on a lot of the Ibanez range. The in-house (think it may have had a Fishman license slapped on it) preamp in my old Korean C5P was also much nicer IMO, while it worked at least.
Horses for courses obviously, some people love them stock but most don't and people always seem to blame the pickups which actually sound decent enough if wired passive. Every bass with USA Barts in I've played has been excellent, nothing that I'd change on any of them.
My main bass is currently a Cort GB Modern 5 which has USA Nordstrands, Babicz bridge, lic Hishot Ultralites and the lic Markbass preamp in it (which I'm going to change at some point), ended up costing me £460 used after I'd sold the hard case it came with. It sounds light years ahead of the last lic Bart equipped Cort I owned (a B5), most of Cort's licensing deals are a great way to add quality and value to a sensibly priced bass but that MkI preamp is just not for me really.