This cycling computer is the largest-screen model on the market, and it's compatible with loads of accessories - from heart-rate monitors, to turbo trainers, to power pedals, and beyond - meaning you'll be able to map out incredibly detailed training data. Yes, it's absurdly expensive, but it's absurdly good at its job too.
Responsive and large colour touchscreen; Hard as nails build with weather-resistance; Can connect to pretty much any additional training gear - power meters / heart-rate monitors / cadence monitors; Solid battery life;
It's hugely expensive - and there's not much more here over the 'lower' 830 model; Can't use app to setup data screens; Still Micro-USB (where's USB-C / wireless charging?);