Forerunner 265

Hello there,

I'm about to buy my first Garmin watch. I do calisthenics three times a week and run four times a week, with plans to run my first half-marathon and marathon next year—and I want to achieve good times.

I was originally waiting for the Forerunner 275 announcement to grab the 265 at a d

What does a chest HR monitor even add on top of a wrist monitor (garmin forerunner 265)?

Edit: I understand that they are more accurate, but how does that help by that much, I prefer to do intervals of perceived effort and feel with not much HR data