Bike Computer Recommendations

Hey all - I ran with the group a fair chunk of last year but have been unable to since September due to back and foot injuries. Fortunately I'm on the mend and able to start running again but will need to do a lot of biking cross training to keep the load off from running while I build my fitness back up. 

I've biked on/off for years but never invested in a bike computer (just used my watch or phone). To the bikers out there - is it worth it to pick one up? If so do you have any recommendations (note: I have a Garmin watch already if that changes your recommendation)? 

PS - if anyone is looking to ride I'd be down! 

Thanks!!