Happy holidays!

It's about time to replace my idler pulley and tensioner. I did not do that last year when I changed the belt. Now I can hear some noise under the hood.

Spend some time searching around and, for the idler pulley alone, I found many options from less than $20 up to more than $300 per unit. I have read people recommended the OEM instead of OE or aftermarket. I can understand that. However, I have found some expensive ones. To justify their prices, they claimed their units are so efficient that they can bring back 10HP. I would like to get some first hand info from people who actually used them for a while. Are these expensive pulleys worth the money? Are they built to last longer? Can you really tell the difference in getting 10 more horses?

In terms of tensioner, it seems like OEM hydraulic is the only way to go. Is there any high performance option? What are the advantages of using them? It seems to me there is nothing wrong with the old plate. Is there any reason that I need to replace the plate? Thanks in advance.