I would ignore the reviews on MTBR, there's nothing wrong with the Deore derailleur at all and it's on sale for a great price. My teenaged son has one on his bike, it shifts as smooth as silk. And if it can survive the abuse he puts it through, I'm confident in saying it's a very durable derailleur. Sure, you can go for a more expensive derailleur, with the gearing you have you could probably even get away with using a long cage "road" derailleur. But in terms of performance and durability, you won't do any better than the Deore, and it's $17.99-