This gadget just works! Comfortable, easy to use and reliable. This model supersedes the MYTrek and pleased to report this seems to have none of the communication issues commonly reported with that. You do have to move it around a bit on first use to find the best place for it to detect your pulse, but once it does, it's maintains transmission. I found it better to place the sensor towards the inner aspect of the upper forearm, strap firmly fitted, but not so tight it's uncomfortable or restrictive. That's the hardware! The software (app) that goes with this is very basic and didn't find it useful for my training. I downloaded the iCardio app. Works with this device, app is free, but you do have to pay for various options, including linking the Rhythm sensor (£1.99) or pay a one-off charge of £5.49 to unlock all functionality, which then allows you to set up fully customised routines and a multitude of other options. This is one paid-for app well worth the outlay though, given that the app associated with the hardware is so basic! I have rated 5 stars as the sensor is great! Unfair to down rate it because of poor associated software, as other apps make full use of its abilities. A little note on the charging dock, which was also a bugbear with the MYtrek: To undock easier, place both thumbs on the back, fingers on the ends and 'press' the band off, like popping a pill out of a strip.
If you use heat rate and training zones in your routine and like to see illustrated stats, the Rhythm band and iCardo app are a great combination.