The one shaky area in my kit is/was the telezoom end. I really like two lenses, the Quantaray 100-300 and the Pentax DA±L 55-300 - and I've owned each several times. Why? Well the Pentax lens has more range, faster aperture at tele (f/5.8 vs 6.7) and in some cases includes quick shift; the Q-ray is decently sharp, faster to focus, and both smaller and lighter. Each has its merits, so I keep alternating.
I just found a mount-damaged DAL for $67. We'll take the chance that it may be irreparably damaged but hopefully I can rip parts out of another lens for it. At that price, and the approximately $30 net that I paid for the quantaray: why not own both? :^)