Originally Posted by
Little Darwin
It will work, but I have that exact Deore RD on one bike, and I notice no difference in how it shifts compared to the Acera RD I have on another bike.
If money is an issue, ignore the posts you have read blaspheming anything below Deore, and ride what you have.
If it makes OP feel better about his purchase, it is his money. I don't remember doing this, but I may have upgraded the rear derailleur on my '97 Bianchi hybrid. It has an STX rear derailleur, but according to Bikepedia, the bike came stock with Alivio . I don't remember swapping out the derailleur, so it is either something the LBS did without my knowledge (do LBS do free hidden upgrades?), or maybe something I asked them to do but forgot about.