Rectifier, anyone used the ESR142 Electrosport?

[Meme]

My GZ250 is not charging the battery. The voltage across the battery is about 12.8 with the bike off, and drops down when it's running. As the RPMs go up, the voltage seems to drop a bit, but is not always the same. The bike runs great when I charge the battery at 2 amps, but starts to buck and die after 30 minutes to an hour of riding and the battery has low voltage. The battery still has 12.8 volts after sitting for a week after charging. The battery connections and grounds have been cleaned and seem fine. Everything I have looked at points to a bad charging system, the rectifier/regulator being the weakest link.

My question is, has anyone used the aftermarket ESR142 rectifier?

There is one on eBay from ElectroSport for $69 with free shipping, and cycleplicity has a Procom one for $46.38 plus whatever the shipping is. There are also used stock ones on eBay ranging from $15 to $80. I would rather have a new one than a used one, and the aftermarket ones claim to have a better design, however, I know claims aren't always true.

Anyone here have any experience with the ESR142?

Thanks for any help,

Brizz