I am considering upgrading the rear derailleur in my commuter bike since it has some considerable scratch damage and since I have to change the rear freewheel / cassette for some functional damage.
While looking at the entry level Shimano components, I started considering the Altus RD-M2000 / Acera RD-M3000 / Alivio RD-M4000 since they are still cheapish (at 20 something, 30 somthing, and 40 something USD respectively) and they are "shadow" (narrower profile and stronger tensor spring to reduce chain whips/bounce and have a lower chance of them "shifting in a bump" or coming off altogether)
Are the shadow vs non-shadow rear derailleurs better for bumpy commutes? (rather than just for downhill/way bumpier rides) Are the Altus / Acera / Alivio comparably durable? Should I go for the cheaper Altus one or the Alivio one if I can spare the extra bucks?