The higher you go, the easier it is to get light on the floor without getting it into peoples eyes. The downside is the higher the stand, the more prone it is to tipping, so you need heavier stands or weights for safety. For most smaller events, I use a 4Bar up about 8 ft or so with an Ultimate Light Stand (I have 2 LT99-BL).
I have two light stands, and both only go up to 9 feet. I only use one stand for my gigs. Not willing to do any more setup than that. Crank stands are nice, but heavier. Since my current mindset is to downsize, get lighter, and reduce setup time, it's unlikely I'll make much of a change on the lighting front any time soon.