derailer reliability
 

do higher end derailers, say a 105 require less adjustment than say an alivio?
Or is it that higher end derailers will shift more efficiently but still require as many adjustments.
Mind you, I'm talking about routine matters over similar terrain and mileage, not trauma

As long as you don't bump it into a rock or curb or something your rear derailleur might be the most reliable component on your entire bicycle. Once the cable housing ends are seated so the cable tension stays constant they seldom require any adjustment.

I've been riding derailleur bikes since the 1960s. It's my experience that derailleurs, once set up properly, need virtually no adjustment over many decades of use. Cables may degrade, elongate from their initial length, pulley wheels can wear, or the derailleur may suffer damage in a crash or through abuse, but derailleur settings don't need to change.

Cheaper derailleurs can wear at their pivot points and get "sloppy". The tension bearing pulley/cage spring can also weaken on lower end derailleurs, but this takes many years of use/wear. From a practical standpoint new *out of the box* modern derailleurs give you reliable use for as long as you have the bike.

Alivio is a 7-speed wide range hybrid type derailleur. 105 is [now] part of an 11-speed road group. Both work fine for their intended purpose.

yep, dr's are a set and forget about it item...the more you mess with it, the more you have to.