Agreed! I love the 498t, I prefer with a 496r neck to the 490 though, I'm also a big fan of Burstbuckers when in the mood for PAF type pups, a 498 or BB3 can do some killer heavy rock!
My experience with the 498T/490R is very mixed. I have 2 90s Les Paul Studios (Ebony fretboards) and the pickup combo sounds amazing in them. I have a 2001 LP Custom and the pickups sound anemic as hell in that guitar (waiting to put a 35th anniversary JB/Jazz set in). Maybe the modern ones are just dull? the 90s ones sounds great, or maybe thats just some "vintage magic" happening to the pickups as they age.
As for pickups that are within the output range, the Custom 5 and Jazz/59 neck would be on par output wise.
No experience with the 498t, but the 490r is probably the worst neck pickup I've ever played. I've had them in an SG, Les Paul, and a Jaguar. They're mudbuckers. Replaced the one in my SG with a Pearly Gates (later a Wolfetone Marshallhead neck) , Les Paul with a Jazz (later a Wolfetone Legend), and the Jaguar got a Jazz too. Magnet swapping will help, but it's kind of like polishing a turd.
I can't compare the 498T to anything Duncan does. The 498 is a solid stock pickup, to my ears. It's on the hot side of the output spectrum, but it rocks for hard rock and metal.
The 490T is my least favorite Gibson pickup, my a longshot.