I have the RPS7200 - on the whole it is a pretty decent scanner when used with care, though I've found you need Silverfast to get the most from it (Vuescan doesn't really get on with it very well). There is no automatic frame detection. You load the first frame, adjust the offset manually and then Silverfast just sends a command to the scanner to advance one frame - it does this with a standard number of stepper motor actuation's (I suspect). If you have non-standard frame spacing, or irregular frame spacing, then you'll find that by the end of the strip you are a little out. As others have mentioned, it also sometimes slips a little pulling the film through. I've found this worse with some films (Portra slips most for me), though it's much better when put through shiny side up. Give the rollers a good air blast from time to time too as dust seems to make them slip. It never achieves the stated 7200 ppi resolution, but does get close or exceed 4000 ppi. It can reliably resolve 3600 ppi, so you can either just scan at that, or I have found that scanning at 7200 to TIFF with iSRD (colour or chromogenic films only) and ME on as an archive and then USM then then resizing down gives better results than straight scanning at 3600. This takes time though.