This difference may be due to staffing levels. I have only flown Regional Business Class on CX, and my experience (especially on the 777-300 which has 56 Business Seats) is that the service is assembly-line like. Entrees are not plated on board, but served in casserole dishes, beverage refills were limited, and no post meal or pre-landing beverage service was offered (on a 4 hour trip from BKK to BOM). We had turbulence, so per CX policy, hot beverage service was suspended, but the F/As didn't bother offering a water/juice service instead.
To offer quality service and to individually plate entrees would likely require more F/As. When I've flown both long haul Raffles and regional Business Class on SQ, F/As are always running around serving me, and the meals are always nicely presented (regional meals may be pre-plated, but they end up looking nicer - maybe because the dishes are bigger?).
I remember getting about 5 refills of green tea (each time in a fresh cup) flying SIN-KIX, all within about a 20 minute interval. So does anyone know if SQ staffs more F/As than CX for a comparably sized cabin?
They offer the proper course-by-course service on the outbound flight to DEL, so staffing is not the issue.
Methinks AA uses the late departure time as an excuse to be cheap.