There used to be a more detailed feature comparison PDF document but it seems to go missing with every update, and in any case I don’t recall it ever going into that level of detail. It is however mentioned as a “Cubase Pro only” feature on page 983 of the current English 8.5 manual, but who reads manuals, right? Especially not one that weighs in at some 1400 pages, and certainly not prior to purchase.
Not to defend the absence of detail in the feature comparison, but I suppose the marketing people need to differentiate somehow between the “Pro” and “non-Pro” editions, and this feature is unlikely to crop up very often amongst the Artist target audience. The clearly intentional exclusion of some NTSC-based framerates in Artist does seem like a bit of random discrimination though.
I suppose the thing to remember is that as far as video is concerned, Cubase (even Pro) seems to be the poor relation of Nuendo, the flagship post tool. IMHO it’s an issue for the placement of the various products that Nuendo wouldn’t necessarily be a musician’s choice for composition, yet Cubase has very limited video playback (and no export!) capabilities. There’s a re-write of the video engine taking place at the moment to eliminate the use of QuickTime, so perhaps we can hope for better in the future.
As a possible workaround, the conversion of 23.98/23.976fps to say, 29.97fps for use as a guide track is quite straightforward using external tools, and remember that a soundtrack usually needs to be temporally correct and not necessarily frame-accurate, so it is possible, though not optimal, to work with NTSC-based footage in Cubase Artist as long as it’s all in the box, and no sync with external devices is required.