I second the use of Insure My Trip. Excellent website! I've personally used Travelex, among others, and have made a claim with them which was easily and relatively quickly resolved. I find that their coverage is a nice middle-of-the-road coverage that isn't too expensive, but covers a lot of what I want.
Note that most trip insurance won't cover the value of points-reward airline tickets. Some will cover the charge the airline will charge to "re-bank" the points, but that's generally about it.
ABD is always changing their policies, it seems, but last I heard, they covered your flights if you fly to and from the start/end points of the ABD. But they won't cover the pre-/post-days you book yourself. (And again, they won't cover the value of the points, but if you have other claims - lost luggage, trip interruption, etc, they should cover that.) I'd always check with ABD or your TA before deciding on ABD's policy.
Sayhello