Great review Frosty. I purchased the Mega XL for my son last year 2nd hand on BH loved it so much then immediatly got myself the Mega C also 2nd hand on BH. I have also been using wrist based watches for the last few years also the 310 XT and the 920 XT suunto ambit and suunto spartan. i decided to get a head unit for cycling to save the wrist units a bit and also it is annoying having to look on your wrist when riding. the wrist based heart rate while cycling is also suspect. I love the unit. so far i have paired it with , Bontrager Speed and Cadence sensor BLE and ANT+, Garmin ANT + HR strap , Cycleops Powercall BLE and ANT + and Lezynne HR monitor. The bike mount it comes with has a knack to crack , so my mate 3D printed me 4 out front mounts. they work like a charm . DO NOT buy the Lezynne HR monitor. IT is a SCHLEP. You have to remove the battery after EVERY ride as the sensor does not stop transmitting by itself. I cannot fault this computer and it is TOUGH. Battery life is amazing. The app has limited reporting and some earlier versions of the app kept crashing . the latest update is super and just keeps doing it's thing. If you are used to Garmin connect be prepared to be underwhelmed by the Lezyne Ally APP. However the Desktop site gives more details and analysis of your rides. I am curious to know if any body has paired their Lezyne lights to their head units on how that works. You apparently get a myriad of light settings.