I travelled on both AI recently and UA early last year to DEL. Frankly I dont see the far superior product. Both have lie flats, food is much better in AI, on IFE United is better (larger screens and more choices of English movies, but not for an Indian origin traveller who may also want more Hindi and Regional language movies (UA has some Hindi but none regional). The FAs are business like in UA and AI FAs are now more friendlier. The big difference is in the past AI had broken seats, non working IFE, they have improved on that now.