We have always booked a pre-night, and have started adding post-nights too; on our first ABD to Italy we booked our own hotel near the airport and did Rome for a day on our own, then the next day took the hotel shuttle back to the airport and met with the ABD rep for our trip to the ABD selected hotel. We did this with Knights also--but after that, and after hauling bags around etc, we decided it was well worth the extra money to book through ABD, get transported the day before to the hotel, have the same room for an extra night, have breakfast included and see the guides earlier for advice re activities to do on our own while others are arriving on the official first day. Better still--gives us that extra day in case there are travel delays (we went in a day early for a Christmas Market Germany trip with ABD, and were just ahead of snow storms in the US and in Europe--at least two families were delayed and caught up with us later in the trip).
If you can swing the time and cost, a post-day or two is nice--but also a bit of a let down as you are back on your own during that day or two (no guides to get you around, give you water and snacks, entertain the kids!)--but it was great to have the transportation to the airport in place.