Excellent, another L replacement that will be four times as expensive lol
Well, i have had two Canon autofocus lens brake-downs, a 28-105mm and a 70-300mm, neither L-series lenses. Neither much used and well taken care of.
Canon obviously does not produce good quality cheaper or mid-priced lenses.
I am happy I could read about your similar problems with your 50mm 1,4 usm, so I can avoid it.
I currently have the 24-105 L and 70-200mm L lenses and also the 20mm 2,8 non L. Seems good quality so far, but who knows how long they will last?