The RAAS is really a wonderful tool; I just hope it doesn't lull us into absolute complacency or consign good airmanship to irrelevance.
Actually I think it is pretty bad. It constantly states the obvious "Approaching RWY 26R". By constantly announcing this, the perception of the "callout" slowly sinks towards the subconscious. I hope I will realise it calling out the wrong number, if it happens to me. It behaves as if GPWS would call a terrain warning on every approach. The only thing is the "on taxiway, on taxiway" call, that might save a bad one someday. I just find it psychologically underdeveloped.
It should be designed as an alarm system, that only speaks (warns) when something does not go according to plan.
Maybe you feed the taxiclearance into a box, and it should show you your position and route on the EFBmap, going into alert if you deviate from it.
Nic