Soft focus

Upgraded from Olympus 5050 to D70 18-70 kit. Happy so far with everything except the focus. Seemed a bit soft, unsharp in Capture. Started to do a side by side comparison (C5050/D70). Both cameras with no sharpening, I noticed that the olympus was far sharper. Landscapes with the D70 were at best soft. Recently bought 12-24mm DX lens. Even worse results. Reviews of this lens have quotes like"stunningly sharp" and "breathtaking images". Over 5000 shots taken with the 5050 and a C350 before that and countless film shots from a Canon SLR. Many test shots and expletives later, trying to decide if there a fault in the cameras hardware. Never heard of two (nikkor) lenses giving such poor quality results. Any thoughts regarding this matter greatfully accepted