What is better Airbus A350 or Boeing 787?

The A350 and the 787 are not really in direct competition, only the smallest A350 (A350-800) competes with the largest 787 (787-9). So I shall compare these two aircraft. It must be remembered that the A350 is actually in competition with the 777 and that the larger variants of the A350 will have better statistics than the stats shown below.

Passengers (maximum): A350-800: 440 787-9: 290

Range: A350-800: 8,500 nmi 787-9: 8500nmi

MTOW: A350-800: 259t 787-9: 251t

MLW: A350-800: 193t 787-9: 193t

Cruise (Mach): A350-800: 0.85 787-9: 0.85

Maximum (Mach): A350-800: 0.89 787-9: 0.89

Service Ceiling: A350-800: 43,100ft 787-9: 43,000ft

Engines: A350-800: RR Trent XWB 787-9: GEnx or RR Trent 1000

Maximum Thrust: A350-800: 79,000lbf 787-9: 71,000lbf

Cost ($millions): A350-800: 245.5 787-9: 200

As this comparison shows, the two are very equally matched, the only differences being cost and seats but these two cancel each other out. Sales cannot be compared yet as the 787-9 is already available whereas the A350 isn't.

As I have previously said, the A350 and 787 are not in direct competition, with the 787 being a large variant of the family and the A350 being a small variant of the family. To summarise, the 787-9 is a big version of a smaller plane with smaller engines whereas the A350-800 is a condensed version of a large airliner. This means that the A350-800 is a more advanced airliner (e.g better and more powerful engines) than the 787-9 and if cost were no factor, the A350-800 would be the only choice for any airline.