Garmin 305 vs. Polar RS200SD

Right now I have a Polar RS200SD, it's more for running than anything it doesn't have a bike computer or anything of that sorts, it just has a foot pod to measure my distance. Tracking my running distance and it's ability to go into the water are the main reasons that I got it. I'm not looking to place in my age division, I just do triathlons to have fun. I'm doing an Olympic Distance in September and the rest this year are sprints (4 sprints, 1 Olympic, possible 1/2 marathon). Next year I want to do the Califronia 70.3. Should I go for the Garmin 305 Forerunner since there is the rebate that's out right now or stick with the Polar. After buying the Polar I don't use during my swim workouts, but am considering using it for when I do my triathlons. I have just started using a HRM and can see the benefits already. Thanks for the help.