I am a physician and tested the unit against other ANT units and it measures up fine and is equally as accurate. It is very nice to be able to use a Bluetooth unit that syncs perfectly with the iPhone. With that said I have used the unit for about 2 weeks of testing so far and so cannot be sure of the long term reliability. There are some concerns:

1. During one of my runs the unit outputted a heart rate of over 1 million causing the program to re-calculate my average heart rate in the hundreds of thousands. I don’t know if this is a common occurrence or if it was an isolated incident, but I have never seen that happen with other units. It’s also possible that it is related to the Bluetooth software on the phone.

2. The strap is pretty flimsy compared to those from more expensive Garmin ANT monitors. On the plus side this makes it lighter, but on the negative side this could result in the strap breaking or the leads failing much earlier. It’s hard to know for sure. Garmin units are usually rubberized in this section and contain the monitoring leads built in. These are patched onto elastic bands and appear to be a relatively thin.

The product comes without the names of the programs it is compatible with, just pictures. My suggestion is to have the actual names so we can find the apps as pictures don’t cut it.

I have now used the device for a few months and the aberrant heart rate of over a million never recurred. I have observed over time that the unit does not work well if it is dirty & if you don’t have it wet before you put it on. I recommend washing it and then putting it on your skin while it is still wet. This seems to work fine, otherwise you may wait up to 5 minutes before it starts registering. Other heart monitor belts that I have used are NOT as sensitive to needing water & to being clean. I’m guessing that this is because the construction of the leads is a little flimsier than heavier duty belts with the leads built in. The transmitter piece pops off and it looks like the battery is easy to replace. I have never had any problems with syncing it to the Bluetooth heart monitor apps and have used Wahoo Fitness and Runkeeper. Since the device can connect to Bluetooth audio and the b heart monitor at the same time, it is almost certainly using Bluetooth 4.0 (also called LE or Smart) which uses lower power similar or better than ANT. I would therefore expect the battery life to be as good as any traditional belt. Keep in mind that Bluetooth 4.0 is simply a different Bluetooth chip inside your phone sharing the same antenna. This means older phones won’t work with the belt (ie only iPhone 4S and above & more recent Android Phones). It also means that the pairing process is NOT the same. You pair from within each app you choose and NOT from the settings manual. This means you have to hunt for the pairing instructions for each application and they are all different.

I have had this monitor for two months. It has worked great until last week. All the sudden it is giving erratic readings while I am running, anywhere from 80 to 190. It is totally useless now that the return time period is over.

Paired well with apps but heart rate was not accurate, it jumped all over the place while not moving a muscle and didn’t improve with exercise. I even tried re-adjusting the strap to make sure it had good contact with my skin.

I expect a heart rate monitor to be at least good at its primary function, I am returning and ordering a Polar H7 (rated well for accuracy).

Update 5/30/13: Mobile City sent me a complimentary unit and it works great. Paired with my iPhone 5 immediately and works accurate with mobile apps, heart rate doesn’t jump around like the first unit I purchased. I am impressed with the customer service provided by Mobile City.