First AC is basically a losing proposition. Let's face it; the poor go via general and SL classes; middle classes via SL and 3A; while rich either take 2A or just fly. 3A books first followed by 2A and then 1A[half of 1A seats are reserved for VIP's which is why WL 1 or 2 is easily confirmed]. On routes that have air services, 1A basically loses. Unless you are out of options or are extremely rich, there is no reason why you had take 1A. Whilst you may get personalized service in 1A; barring a few trains, most can't sustain it.