Slides are dead easy to load, just slide them in the holder, the holder advances very easily in the feeder and you just have to remember to keep it straight because it is possible to vary the angle of the holder ever so slightly (although this can be useful if you have a slide which is slightly wonky in the mount).
Negatives are a little harder to load, but once you've got the technique for getting them in the holder then their dead easy as well, just fold the holder to 45 degrees put it on a suitable surface with the ridged part facing up towards you on the angled bit and then balance the negative on the ridges (lining up the negative frames inbetween the frames on the holder) and then carefully pick up the holder and bring the hinge shut, then clamp it. Really curly negatives can be a little difficult but their still fairly easy to get in.
Its quite quick when scanning at the maximum 3600 dpi and multiexposure obviously doubles the time taken but increases the dynamic range further which is extremely useful on slides (it has no use on negatives). I would highly recommend getting Vuescan though if you don't have it as the Cyberview software that comes with it is basic to say the least.
If you want an auto-loader then the Reflecta RPS 7200 professional may be of interest although it only does it on negatives (you just slide slides into the slot every time) and is about £100 more, I did consider waiting and getting one of them but decided the Proscan 7200 was good enough for me.
Sam