I generally find the random mode produces a mix of shots of a style similar to the reversal film and bleach bypass modes, but with varying over and under exposure, split tones and saturation. There are probably a bunch of other variables, but yeah you'll get stuff much nicer than the standard set of three defaults if you take the time to look for them.
And yeah, I'd say calling it useless is like someone saying using cheap old off brand lenses is useless. I've been shooting RAW for a long time, and having found a method of processing I finally love in Lightroom, I've decided shooting in RAW just isn't as fun. I've got myself on a non-photographic career path now, so I don't have to worry about being professional or creating masterpieces anymore. I can create photographs.
I've literally only just started using the cross processing mode despite having access to it for years. And it's great, I stumbled across a lovely blue one with slightly subdued saturation, good sharpness, contrast and a bit of over-exposure, and it looks fantastic to me. Shooting with that or my yellow or red preset is, to my eyes, no different than choosing a specific lens to shoot with. RAW gives you huge flexibility and potential, but I just don't think it's as fun. Somehow shooting in JPEG and knowing it's fixed and very hard to alter from it's origin (especially as you don't really know what that origin is with cross process) makes me feel more creative and driven. I'd never shoot it for a job obviously, but for personal stuff I'll be glad to see the back of RAW.
So yeah, set it on random and fire off a ton of frames as you walk around. Find a bunch you like the look of, save them as favourites and enjoy the cross process mode
It's much more pleasing than the other filters available in the camera methinks.
As a tip, you can't alter the white balance and I'm pretty sure it sets it to automatic. This means that indoors things will generally have a yellowish hue anyway, so powerful yellow split tones look a bit overdone. Blue tones are nice for stuff like that. Be mindful of over-exposed and under-exposed presets when you find them. And I find the results generally look beautiful when flash is used, even just the on-camera flash. It makes it look incredibly amateurish, but more authentic as a memory in that case. I've taken some shots of my rats with on-camera flash (gasp) in JPEG mode (Gasp!) with a cross process filter (GASP!) and they look amazing because they feel like an authentic memory and not a piece of art that I've spent ages editing in photoshop to make it look right. It came out as it is and it's going to stay that way.