AMS-RUH-DXB is perfectly doable, but operated with much inferior equipment (A330) compared two AMS-DXB which is operated by a 772. In fact none of the two aircraft types is anywhere close to state of the art and with AF offering soon 2 daily flights from CDG to DXB, they would be the far better choice in every aspect, except on the days when the 77W with the old NEV4 2-3-2 config is operating. For most of the time though they have a mix of 77W with the BEST cabin on the afternoon and the 359 on the evening departure.

I did AMS-KWI-DXB on KLM's 789 in the past and that already felt like a never ending journey (good crew, the usual inedible catering and a rather boring experience overall).