Yeah, I believe we touched on this in the Marathon thread. I agree that the watch is not fully calibrated yet but it has been steady on that number the last couple of times but I still am not totally trusting it yet. I do trust the HRM though, I am finding my heart rate is steady average over even my tougher runs of around 150-155...I hit maximums of 165 or more after long, long runs but I can see that I have a little gap there to give it some more effort but I'm trying to be careful with it.
Yes I do tons of running - it was mostly to lose weight and now to maintain it because of the "run-GER" that I have making me eat more. I do take one day off (mondays) and lately I've been taking another day off as well, or riding a bike instead...so technically I am tapering
On the treadmill runs I go by both - they are pretty close right now. I have the Garmin 620 (no footpod) and initially I was way off..like I'd be off my 1 mile after 1 hour of running and I could never figure out why. Well it was because I had the watch on one hand, and when I run on the treadmill I use one hand to always hold the front bar - actually more like touch it so I can always grab it if I miss a step or something. I don't have a death grip or anything, just need that assurance - it was because I ran on treadmill while on cruises and the sway of the boat would force you to hold on and so I got it stuck in my head. Usually I also just focus straight ahead or on a movie and I might tend to start leaning too far and could fall off so I use it for assurance....ok, long story, sorry. The main thing is that I realized that in doing that it was screwing up my distance readings - I thought the Garmin 620 was using the HRM accelerometers for pacing info but it turns out it is using those only for the cadence, ground contact time, vertical oscillations and the main watch for the pacing info when no GPS is available. So after a few outside runs it gets calibrated to your stride length and then on the treadmill the accuracy will be better compared with the treadmill. For me, it means I have to hold the watch in the one free hand that is not touching the front bar, but I've been able to match closely - usually off maybe 0.1 miles or worst case 0.2 - some of that is due to me switching hands occasionally.
Thanks for the suggestions, and good luck to both of us...

I'll stop hijacking your thread now!