I think Grandview does have those four qualities already, which is why I don't know if the value there is really going to appreciate that much in the next decade or two. Generally speaking, if you're looking for a real estate investment that is going to really grow over that amount of time, you're going to be looking in an area that has fewer of those qualities, or even none of them... but instead has the potential to grow into them.
Buy low, sell high, right?
That being said, my short list of places to invest for the 10-20 year range includes:
1) KLD (of course... I live here)
2) East Franklinton (east of 315)
3) Weinland Park
4) The Parsons Corridor
Each of these four neighborhoods have their own good and bad characteristics... but most importantly, they are all beginning to see both public and private investment that is going to slowly pay off on the long term. And each location has great proximity both to downtown as well as existing established neighborhoods.
Of course, you're left to deal with some less than optimal elements while the neighborhood transitions.
Just my two cents. I'm no expert on this stuff, but I feel as if I keep tabs on enough of it to make a somewhat educated guess. ;)