I have been using a t6 for triathlons and marathons for about 4 years. I can tell you with total confidence that the heart rate monitor is poor quality. I Run 800-1000 miles a year. The heart rate monitor lasts about 8-9 months before it starts acting up. incorrect heart rate, loses connection with the t6 computer and then becomes useless as a monitor. I have talked to suunto reps about it, and they say there is not problem. The blogs all say the same thing i am saying. every time I send it back to Suunto they just send me a new one. I am now looking to get #5 replaced. Everything else about the Suunto works great, including the foot pod which has 4000 miles plus on it. Just beware of the heart rate belt!!!!!!!!!!!
I also use Suunto scuba diving computers which have both worked flawlessly for 16 years. Suunto is a good brand with the exception of this particular heart rate belt.
Frank

Get the new Comfort Heart Rate Belt. This one worked for a few months, then slowly died. It would start acting up at the beginning of my run and would take it about 5 minutes to dial in my acurate heart rate. It eventually quite working all together over the next month. Changed batteries, reset settings, re-synched it with my watch. Went to all of Suunto's help message boards and tried a few tricks. Still doesn't work. I even synched my Suunto t3 to my friends heart rate belt to make sure it wasn't my t3 that was broken. I believe moisture was allowed inside and somehow damaged the belt.

The plastic ANT belts are really problematic- they only last a few months. Wait until the new fabric belt to comes out- should be soon.

I purchased the ANT, footpod, and bike pod as accessories for my T6. I do a lot of trail running and everything Suunto makes seems to work flawlessly. However, the area where elastic belt attaches to the ANT heart monitor is a weak point on the unit. Not only does the belt fall off too easily during exercise, but the hard rubber of the ANT, where the belt attaches, has now cracked on my unit, forcing me to buy another ANT monitor after only a few months use. I'm hoping the one I just ordered as a replacement is of better quality...