Underdrive Crank Pulley Questions

[ripley's99]

I know this question has been asked before, but the more that i have been reading the more confused i am becoming, and was hoping some of ya'll could help share your insights and comments.

i have read many things that suggest underdrive pulleys cause bearing wear and damage to your engine, and also drain the alternator. but if the pulleys caused as much damage as people say, then why do so many companys sell them? people that i autocross with that have '89 civic si hatchbacks have the underdrive pulley and seem to have no adverse engine problems, or alternator drains, and these are on high mileage engines that are also used as daily drivers.

i was wondering if anyone here has the Unorthodox Racing underdrive pulley on their camry and what your thoughts on it are. i also know that the whp gains are minimal, i just want to gather as much info as i can before i install it on my car, which is a gen 4 5-SFE auto.

Thanks in advance for all the help,
Keri