I did the Blackberry Cobbler 100 miler today in incredibly warm temperatures in NC. We were already in the high 60's in the early afternoon.
While I don't have anything to base the numbers on, I'm assuming the Garmin 305 is a little more accurate than my Ciclosport. At least I know the mileage is more accurate with it based on the GPS system. I rode in a pack or group of other riders and there was no interference or crosstalk between my unit and other folks electronic devices which is good news. Also, the cadence and speed displays worked perfectly in that there were no spots when it didn't provide any data which to me says the cadence/speed sensor (I realize speed is primarly GPS unless there is no GPS) is working well.
The grades for the hills seemed very close between the Ciclo and the Garmin. However, the Garmin indicated that I had about 10% more climbing than what I had recorded on the Ciclo for the exact same route (I've done it 6 times in the last 6 weeks). That was good news!
Apparently there were a number of Garmin's in the group of people I was riding with today. Everyone who had one, had programmed them for "autopause" so every time we came to a stop at an intersection you would hear a lot of "beep" "beep" from the units going into pause and then unpausing as we starting moving. I thought that was kinda funny......Maybe a new marketing theme for Garmin like Aflac and the duck......Beep Beep!!
I'm not sure about the algorithm that is uses to calculate calories burned but it indicated that I burned over 6200 calories today. I really liked that. I have lots of excuses to keep making trips back to the kitchen.
I like the summary reports that gives you data in the different zones and the overall averages but I would like a "data dump" where I could do some queries on the data. As Cheeseflavor/Steve has indicated, the software is okay for high level information but it would be nice to be able to dig into a little more. I'm guessing there is a way to download the information into "for fee" software that will do more analysis. I would also like more detail (more roads) on the map it displays to be able to more easily zero in on specific hills, roads, etc. You can do if you know the mileage but to have a more detailed map would make it easier. I will admit that I have not gone to the Training Center site to see what options are out there as I'm just doing this by the seat of my pants so far (like only read the instructions afterwards!!!).
I am going to need to "tilt" the unit towards me on my stem to eliminate the glare on the glass screen. It comes with a rubber insert to do that. The numbers on the screen are not getting any bigger in broad daylight and it would be nice if they were larger. You can adjust the contrast so the background is lighter/darker and I'll keep playing with that to see if it helps. I could have less information displayed which would make it easier to see when you glance at the screen but the data I have displayed is the minimum stuff I think I need for now (HR, Cadence, Speed, Time of Day, Time of Ride and distance).
While I've only had it less than a week I'm really glad I made the plunge and got the unit. It's not perfect but it's a big leap from where I've been with information and data.