I can appreciate Garmin's effort to get into the cycling/training market. BUT.....

These are issues that I've found:

(1) The GPS tracks in forest but the MPH becomes slower and therefore inaccurate. I compared with the Cateye cyclometer already on my mtn. bike and there is almost a 1.5-2 mph slower difference on average because of inaccurate GPS.

(2) Calories burned is also not accurate. I called tech support at Garmin, and they admit as much. I was going downhill for about 3 miles on my road bike and calories burned showed 345! When I went uphill for a 6 mile climb of 1900 feet the Edge showed 350 calories burned--definitely not right. They need to re-figure their algorithm, and they admit it.

(3) The cadence sensor can be a pain to use. It doesn't seem to work all of the time.

(4) Expensive--it may have the combo of GPS/cyclometer/HR but it's still pricey, and really doesn't any of them well. If you want GPS then take the $350.00 and invest in a pure GPS unit. A cyclometer/HR training monitor can be had for less than $350.00 2 stars

I upgraded to the Edge 305HR after owning the 205 for about 5 months and after deciding that I wanted heart rate information to accompany the wealth of information that was already being captured by the 205.

I've used the new Edge 305HR for about 60 miles of combined road and mountain biking. Like the 205 it captures a wide range of information about your ride - distance, elevation, calories burned, etc.

After following the directions (which involve wetting the sensors prior to putting on the heart rate monitor), I've found that the heart rate information is incredibly reliable. It is great to see, for example, that on a recent 32 mile ride in a hilly area of Northwest San Antonio that over an hour of the ride was at my target heart rate (80% of my maximum heart rate). I upload my info from the Edge and take advantage of the free Motionbased.com account in order to chart my progress.

I have experienced ZERO problems with erratic heart rate readings, etc. that have been indicated in previous reviews of this unit. I'd suggest owners of the 305HR that are having these problems should review the instructions carefully (making sure that the sensors are wet and the unit is snug on the body...just below the breastbone) or contact Garmin to order a replacement.

This unit is working exactly as advertised and will provide a great deal of quality information to help you achieve your training goals. 5 stars

I recieved my Edge 305HR on 2/20 so I thought I would charge it up and take it for a quick spin to see how it works. After 20 miles, I can trully say that "I love it". I have had no problems with the battery life nor any other features at this time. I find this a great tool for fitness training and measuring your heart zones. Set up was fairly easy and we measured accuracy against my old cycle computer on my son's bike. You must be aware that this is a training computer and not designed to be a GPS map like other GPS systems. However, I would strongly recomend using Motionbased.com as a add-on tool (basic account is free). Motionbase has done an excellent job in allowing you to upload your data onto the internet to view your course as well as download other courses from other riders onto your Edge.
Unit also works well with Google Earth to get a satellite view of your ride.
The Gramin preovided software is ok, and could use a manual on how to use it. Once you have downloaded a ride and are able to "copy and paste" that ride into a "course" or "workout" to use again against the "Virtual Trainner". This is very helpful while preparing for centry rides. Various features are really helpful as reviewing your heart rate against various climbs to allow you to pace yourself as well as improve endurance. Also if you are like me and want to burn some extra calories, it's nice to look down and see how many you have burned so far during your ride then view your progress on various software.
The screens are completely customizable and very easy to change.
I have odred the cadence as well and should arrive in the next day or so just so I can also messure my RPM's.
I haven't mastered all the features at this time, but I can truly say that this is the best thing I have compared to the following: Polar 725, Suunto X9, and Garmin Forerunner 301 and 305.
Hope you enjoy! 5 stars

I had high hopes for this unit. Trying to get some one from Garmin on the phone to help may take up to an hour! The sensor is not easy to setup for cadence etc.. Can't get the sensor to work on the road bike. Too much of a pain for this feature to work. Riders need candence. Need to go back to the Polar. Too bad, because I liked many of the features, but perhaps Garmin has too many different products to worry about satisfying the bike rider market. 1 star

The Garmin Edge 305 is a very cool looking unit, and the GPS system is useful for anyone who does not know the territory well. However, my particular unit almost constantly displayed inconsistent and highly variable speed and heart rate readings. For example, on a recent recovery ride, during which I road at a pretty steady pace of 15 mph, the unit displayed HR readings that varied between 120 to 247!!! I have also had problems uploading data from the unit to the Training Center and the Motion Based Agent. On one occasion, the data was simply lost; on another, it showed up with the wrong date (even though the Edge 305 itself displayed the correct date).

When I called Garmin customer service about these problems, I had trouble getting through. When I finally was able to speak with a customer service representative, she kindly offered to exchange my Edge 305 for a new one. The only problem was, they didn't have any in stock -- at the manufacturer!!!

My experience with the Garmin Edge 305 confirms my theory that the more you pay for a cycle-computer/heart rate monitor, the less reliable it is. 1 star