Originally Posted by
common man
or are you saying that the front derailers all perform similarly unless going to xt, xtr, etc.
This. Front derailleurs are pretty much the same unless you're comparing one end of the spectrum to another(Deore vs XTR).
Originally Posted by
common man
i've heard that the cassette sprockets make a big difference in shifting too
High-end cassettes have better-shaped teeth for cleaner shifting,but again,as with front derailleurs,it's only noticable between high and low end.
Originally Posted by
common man
if this is the case then literally compatibility is not an issue but in terms of desired performance (the point of the upgrade) there is an issue with previous components like the shifters.
Like I said,how old is the bike? If it's high-mileage,then things could be worn out. Otherwise,they may just need a good cleaning and adjusting.