Scan of 35mm negative.

Left - Minolta Dimage Scan Dual, right - HP 7400c. Both scans were done at 2400 dpi. USM applied to both: 150%, radius 1, threshold 6. Right image cannot be sharpened any more - horizontal banding becomes pronounced.
Conclusion so far: 7400 is not suited for 35mm film scanning for large prints. Downsizing both images produced almost identical results, so for the web either of the scanners would work fine. Timing: 7400c took about 3 minutes to scan 35mm negative.