I just installed the SKS chainboard and have no problems with it. I installed it on an IGH bike, though. It's as good as the hebie 391, which I have on another bike. The hebie went on a triple ringed bike. Both of these go around the BB. Both have the ability to extend farther back or closer in (kinda like a trombone).

You really only need to have a cover on the upper part of the chain to protect your pants. A full on chaincase would be good for a bike that sits outdoors all the time. It'll shelter a lubed chain from the elements. I have a bike that sits outside my workplace and will probably do a full chaincase to it in the future.