Bought a Garmin Edge 305 a few weeks ago and have a week to return it. love love love the device except for the lack of maps - not really a problem for my daily commute, but on weekend rides I don't always like to preplan/download the route, and even when I do I find myself deviating from it.
so I'd like to upgrade to a unit with maps, which means the 605 or 705. AFAIK the only differences are that the 705 supports a heart-rate monitor, a speed/cadence sensor, and a power meter
I've been using the heart-rate monitor with my 305 off and on and have found it mostly uninformative. Garmin doesn't use that info to compute calories burned (only on the 500, I hear), and it's pretty much always in the same range for me anyway. plus, I hate hate hate wearing the strap and especially putting it on in front of my riding buddies b/c I inevitably forget until I see the indicator on the Garmin. so that's not a reason to go for the 705
I also don't have much use for cadence, at least not now, though I suppose I could become interested in tracking this at some point. and I'm sure as heck not shelling out the cost of a bike for a power meter anytime soon
for me, I guess the only advantage of the 705 is that the speed sensor lets you use the Garmin when spinning on an indoor trainer - you would otherwise appear motionless to the GPS. I don't normally train inside as I find stationary cycling boring/unmotivating. I'd rather be outside in the cold with lobster mitts and booties
so...I'm thinking I'll save $80 and buy the 605 (and use the $80 to buy the maps). am I missing anything?