dean ace, experience w/ bearings? [x-post w/ passion board]

I'm wondering if anyone has faced this issue (x-post w/ the passion board): I'm trying to decide whether to retrofit the main pivot of my Dean Ace. The main pivot on this bike pivots around the BB, using a design they share with Lenz. The BB threads into a smooth shell, which then rotates inside bushings -- originally delrin, now brass (I'm on my third and have overhauled the pivot many times more than that).

The amount of maintenance (or play in the rear triangle) is a drag.

Dean will retrofit the frame to use large cartridge roller bearings for $70 since I'm the original owner. This will take 6-7 weeks (yes I'm familiar with their delivery times).

Can anyone tell me from personal experience whether the bearings last reasonably long and whether they've had a good experience with the set-up generally? Maybe someone who has done the retrofit, or maybe has a newer Dean (Lenz too, though I wonder whether the more flexy ti front triangle might be helping it wear fast) that came with the bearings originally?

Thanks!