Lean to do a little bit of "bike tune up" and you can have your lower end shifters & DER's working just fine.
I have basically the same DER's/
I've upgraded to 9 speed and changed the chain rings from 28-38-48 to 22-32-36/38 on my 2 bikes, using the same DER's.
Rear shifts excellent. Front isn't pristine, but it shifts reliably enough for the rare times I'm out of the middle ring.