Check out Rick Steves. He also has family tours. He has a 2 week family tour of Europe this year that is comparable in price to some 1 week ABD. Plus his tours are 100% refundable until Dec, he includes cancellation/interruption insurance in the price and you are forbidden to tip the guides as they are very well paid.
I just came back from my first ABD and absolutely loved it. It was unbeatable for families with young children. However, if your kids are over 8 and you want to get some in-depth real culture, the Rick Steves tours look great. I haven't done one myself yet, but I'm impressed with all I have read and am definitely planning on taking one in the future.
I would love to take one more ABD before my youngest is 10, but the prices are too high for us now. I am hoping that the Gateway tours will be more reasonably priced and that we will be able to book one of those when they come out
As for transfers from airports to hotels, those are so easy it is not worth paying a premium if that is all that you are worried about. Taxis are everywhere in Europe, just have a piece of paper with the name of the hotel you want to give to the driver (most likely he will speak some english...they are used to tourists everywhere). You can also often prebook transfers from home, just look it up on-line or call the hotel directly and ask for their advice.
If you can afford ABD and you have young children, they are the best. But there are many other wonderful companies out there as well if you are adults only or if your kids are older.