I have a 660. I use a Mac. I'm in the middle of a coast to coast trip with routes planned in BaseCamp and loaded to the 660. If the few problems occur on the 660 I'm screwed.
No you're not. First, the guy in the article is using the same waypoint for the start and finish -- always a bad idea. Second, I tried importing a route from BC to MS (on my laptop using Bootcamp) and it did not show up with extra waypoints or other weirdness as described in the article. Finally, if a route misbehaves (which can happen regardless of issues with BC), stop the route and re-import it and it should be fine. Also, set your 660 to ask before doing a recalc and as long as you can see on the map how to rejoin the route, say no.
I've ridden many thousands of miles with routes planned in BC and followed on my 660. Are there occasional quirks? Yes. Are they caused by this incompatibility? Don't know. But none of them has left me lost and stranded.
