The 5 wt portion will help each time the engine is started cold. Chances of cold engine valve tick is less because of the 5 wt. Engine wear is usually greatest on a cold engine and using 5W30 will minimize this effect. On a hot engine, the 30 wt portion should theoretically be the same for 5W30 and 10W30.
I'm switching to 5W30 on the next oil change. If Nissan recommends 5W30 for all it's cars as most manufacturers do, that's good enough for me.