I know you have not listed it in your choices but I use the 305. Used to use RunKeeper and various others on the iphone, the 305 is so much better. There is loads you can do with it, it looks a little big in the pictures but I have skinny wrists and it fits and does not look too big when you have it on.
Have not used the 110 or the 405, so I can not comment on them but a watch is 100% better than a phone in my opinion.