I've recently bought a cheapo HRM but am considering a Garmin Forerunner 410 (and annoyingly missed one at the weekend in SC).

What are the benefits of a dedicated unit as opposed to a HRM and Iphone app? I have a Iphone 5 and use Runkeeper and Cyclemeter and gather you can link HRM's to these? I don't want to splash out on a Garmin if I can get the same/better use from my iphone?

My main goal is to improve my fitness and train 'better'.

Any thoughts? I've read a few posts about Heart Rate Monitor's and know the Garmin's are well respected, but just wonder about the comparison. Wasn't sure whether this should be in Watch talk or G&D to be honest.