Mike,
Using a split darkslide on 8x10 is certainly a viable option. I've done it myself many times. The only real problem I had was with wide and ultrawide lenses - and this is mostly a function of my 65 year old 8x10 camera that isn't exactly what you'd call wide angle friendly. With the 30" original fixed bellows all scrunched up, there just wasn't any flexibility left for movements with a 150mm, let alone a 110mm, lens. I couldn't even get enough front rise/fall to center the lens on the 4x10 film area. This was compounded by the fact that my wide and ultrawide lenses didn't have a lot of excess coverage. Of course, you can just center the image on the 8x10 film and crop when printing, but then you only get one image per sheet. This, along with the smaller size and lighter weight, is why I ended up going with a dedicated 4x10 camera. Like I said, more than one solution to the problem. If you have a newer 8x10, especially one that can use a bag bellows, or if you don't use really wide lenses, this probably won't be an issue for you.
Kerry