I recently flew ORD-FCO with a 10-week old and got the bassinet seats. I booked and selected E+ seats and then called United immediately and they moved me very easily to the bulkhead where the bassinet existed both ways. No big deal. Definitely made the flight much easier. The bassinet spanned all the aisle seat and part of the middle seat of the middle section bulkhead. There was still enough leg room for me (at 6'3" who was in the middle seat) and it's pretty high up. Just not as easy to get in/out, but hey, easier than if they're on your lap! And, as stated, can't use it during takeoff and landing and I recall the weight limit being quite low. I'm definitely glad I did that instead of ponying up for a third seat, but I supposed there's some risk involved as it's not 100% guaranteed. You have to ask for it when you get to the gate/get on board. Note that United did charge me 10% of the adult fare for the lap child as per their policy on international flights apparently. And given that I booked fairly last minute on miles, it was more than expected since they based on the revenue ticket at time of booking.