In addition to the battery drain of having the phone screen on all the time, I don't want my phone that exposed in case of a crash. I carry my phone in my jersey pocket.
The most commonly used GPS bike computers are Garmin and Wahoo. Garmin has a wider product range. My personal choice is the Wahoo Bolt. I'm not familiar with Cateye's options, or how they compare with other brands.
__________________
"Swedish fish. They're protein shaped." - livedarklions