Hmm. It's hard to say then what the difference is. It could still be the cam weight, but it might be the shape, too. Even though they're adjustable, you can't really get them to the exact shape of any given sprocket. Also it could be worn bearings or loose screws, but I doubt you'd miss that.
Completely get what you mean about the extra money for the 9000s. They're good but definitely not worth the $650 or whatever they go for retail IMO. Mine were some decently worn floor models black-fridayed for $300, which is less than they go for used a lot of the time.
If you need a new double and you dig the 5000s, this is what I would do. Get some used 3000s/7000s. Trashy hinges and driveshafts but otherwise identical to the 5000s (sans red parts). I've seen them go for $100 used, and the main bearings and all the solid parts really shouldn't wear out. Those schmancy dw bearing hinges are a stupid-steep $100 for the pair, but they'll fix half the problems of those pedals. The other half can be fixed by a new driveshaft. My trick one was about $130 and it literally DOES NOT wiggle. Also, you know how those four stupid screws on the dw one gouge the aluminum driveshaft and always loosen up? How would you like one non-gouging adjustment screw on a stainless shaft with 8 ball bearing? You would. Also some rustoleum or krylon is about $4 a can. So you can have essentially dw 5002 pedals that say 3000 or 7000, have all the same other parts, have the best driveshaft ever, and a crappy paintjob...all for about $334. It's Janky, it saves you $70, it works better, and it doesn't come with a case.
What more could you want?