Well the motion does come with a bike mount, and maps. Have you tried both on a bike, a wrist device may be more user friendly, but without trying a handlebar mounted motion, I don't see how you can call which is best.
I'll give you the swimming, though, but I'm not convinced about running. The wrist is far from the ideal place when running, all the arm movements will be recorded, whereas if it's worn on the upper arm only body movements get recorded. I suppose if you're only after a long term average, these movements get cancelled out, but for a short time spurt, it won't be good.
And I must admit I don't understand the swimming thing, the wrist is going to be submerged around 50% of the time. The GPS will have to reacquaint it self every time it comes out of the water, only to be submerged again. Doppler data will be useless, you may get a length speed from trackpoint data at each end, but that will mean the watch will have to be out of water at the start and end of each length. And remember that trackpoints are only accurate to 1m, so if it's a 50m pool you could be out by 10% depending where your watch is out of the water.