OK, have the benefit of having done this with my two kids - 6 months old and 2yrs old - over Christmas.

The bassinette position is infront of the front-most seat in the cabin. You get some dead space because the seats are angled - a triangular shape. There's a shelf at shoulder level and the skycot clips onto this with press-studs.

It's relatively private as - at least on the 747 - the toilets are behind you so the only traffic going forward is the crew.

Lap child (as in just under 2 yrs old) it would be terrible as the seat is so narrow and the walls so high.

Child in own seat - again not very good as it's difficult to help them eat, and they're pretty isolated on takeoff. I was able to sit on a pillow & blanket then fasten my seatbelt and just reach over the partition far enough to hold my 2yr old's hand.

CX were completely unhelpful over the matter and wouldn't even consider switching us to flights with old style J class seats.

I really would say AVOID if travelling with anyone between 6 months and probably 7 or 8 yrs old!