Pros:
– Thinner and lighter than the FR210
– Color display with better resolution
– GPS signal works well, even in midtown Manhattan, where it’s densely populated and loaded with skyscrapers (average satellite lock time: 5-6 seconds for me)
– GPS is accurate and reliable. I have yet to experience problems. Will update if this changes.
– Heart rate monitor (bought as a package) and Bluetooth to iPhone work well
– Waterproof so I don’t have problems with sweat or wearing it when I shower
– Variety of screens you can choose from to display data during your run
– Can transfer data via Bluetooth to my iPhone app (which is linked to Garmin Connect) or through the cable provided
– Garmin Connect is actually quite useful in detecting patterns in your training, monitoring the physiological responses you have during various types of workouts, and sending training plans to your watch
– Functions and buttons are very intuitive; I spent less than 3 minutes looking at the manual before mastering the watch

Con:
– Wish there were more color combos (like all black)
– GPS takes forever to establish connection with the satellite for the first time (but it is very quick after)
– The Garmin Connect app on the iPhone is a bit glitchy, but tech support said they are already working on updates
– Battery life was very average in this day and age

This watch is probably one of the best I’ve seen in the market for a while. The 0 (or 0 if you get the heart rate monitor with it) is well worth it if you actually use it/serious about running. This little device will tell you everything you need and want to know about your body and your training. If running is a hobby, then I suggest just using mapmyrun.com and/or just getting a simple wrist watch. The value lies in being able to train on heart rate and logging decently accurate mileage (not accurate enough for tracks) without having to map it out beforehand.

As a competitive runner logging 60 to 80 miles per week, I would recommend this watch to runners who are serious and want to be scientific with their training.

I’ve had this watch for about 10 days now and I’ve only gone on 4 runs, each about two miles long.I am loving it so far. My main complaint would probably be all the hubbub that went on with many stores claiming these were in stock and not actually being in stock. But I’m sure many of those inventory problems have all been settled.

Pros:
* Very low profile and works as an everyday watch. Love that I can just always be wearing this and can just press the RUN button a few times and go.
* The band is removable. One of the main reasons I went for this particular watch was that the wrist strap is changeable. I had seen too many people post pictures of their old watches with a tear and having to use duct tape to keep it together. Some people have complained that it feels cheapy but I think it’s fine and would last a while. I believe Garmin sells the replacement bands for about or so.
* GPS preloading is great, ready to run within seconds of going outside.
* Indoor treadmill tracking has been pretty accurate. Just turn off the gps and the watch will use the integrated accelorometer to calculate your distance. When you’re running with gps, the watch will use the gps data in combination with your arm movements to make calculations when there is no gps.
* So much customization! It was a little overwhelming when I first got the watch but it’s pretty intuitive and does not take long to get used to.
* Little bit of color in the screen is nice. You can only pick one theme color at a time but it still looks nice and is customizable.
* Not sure if the cadence is measured by the watch or the HRM monitor, but that’s interesting information to have as well. Apparently good runners get around 180 spm.
* I haven’t used it yet, but one of the features I liked when I was choosing which watch to purchase was the ability to set RUN/WALK intervals.

Cons:
* The Android Garmin Connect app does not yet work with their newest watches quite yet. Garmin says they will release this soon though.
* I did have one occasion where it took a few tries for the Garmin website to accept a data transfer for one of my runs.

Reading other reviews about previous versions of Garmin watches, this appeared to be the first time that Garmin offered many of the advanced features on their second tier of watches. From my understanding the main difference between this and the 620 is the Virtual Trainer feature, 4 data fields per screen (vs 3 on the 220), the VO2 max measurement, and the recovery advisor. So if you don’t care for those 4 features, I would save the 0 and go with the 220 over the 620.

05/05/14 UPDATE:

Watch is still going strong and battery life is still great. Just used in my first half marathon and it helped me greatly with my pacing. Love it. A few notes:
-As others have noted the cadence is measured by the watch and not the HRM strap.
-The Garmin Android app now works with the 220 over bluetooth, but it is a little slow.
-The data transfer issues I was having turned out to be more of an issue with the laptop I was using, as I don’t have the same problem when using any of my other computers.

This could be a great watch. It may be eventually, if they can get the firmware right. As it stands, it’s not worth the price – the GPS is noticeably poorer compared to other watches – it loses signal frequently, the pace calculations are all over the place, and there are times when it doesn’t appear to have a signal or be looking for one (the satellite symbol is solid green, but the calculated pace is “–:–“). I am hoping the latest set of updates have improved the situation, but based on my experience so far, I can’t recommend it unless you never run trails and you live in an area where the skies are always cloud-free. The walk/run timer and the heart rate alerts are useful if you’re into that sort of thing, but you could get those features for much less money.

*Update 4/16/14*

After the last firmware update, the GPS seems to be a lot better; while the pace calculations can be laggy still, setting pace alerts is no longer completely pointless. I’ve tried running with the watch in a variety of conditions now, and it seems to hold onto a signal much better than it did initially, including extremely overcast days or pouring rain. It drops signal from time to time, but this is much more rare, and it tends to pick it back up faster when this does happen. I wish Garmin would get their software in order BEFORE they released their products, rather than months after.