I have a selenium 398 (non-A) and it's really an incident meter above all. The reflected readings are one to two stops off, but the incident readings are spot on. I think it may be because the meter is keyed for highlights. Perhaps one day I'll ask Quality Light Metrics to calibrate it properly, but I love it for shooting slides and Ektar 100 outdoors. It's light, quick, and accurate.
I just hate the easy-to-loose high slide, and wish it wasn't so damn magnetic.
I got myself a Weston III (calibrated by QLM) for quick reflected metering, and I have a Sekonic Spot/Flash meter when I want more precision. I wish the 398 would be more precise in reflected readings, because it's really a nice tool. But so is the Weston.