I'm thinking about replacing my rear derailleur which is a Shimano Acera with a Shimano Deore 9 speed. Is this a good derailleur? And one of my biggest questions is will it shift under loads well? For instance shifting to a larger sprocket while climbing. Also my cheap Acera needs constant adjustment after long rides (fyi the derailleur hanger isn't bent I checked it), will the Deore require less frequent adjustment?