Seiko are great watches. I have a couple of G-Shock watches and a Garmin heart rate monitor watch. The Garmin is kinda like a smart watch but more practical. It's got all the sports stuff you'd ever need but GPS too. It makes for an excellent daily-driver watch.
I find HRM watches to be very handy. I can tell from checking my heart rate whether I need to slow down my running speed. I can tell if I start running for something how long I'll last by checking my heart rate. If it's in the "anabolic zone" I'll crap out in a few minutes. If it's in the "aerobic zone" I'll crap out when my body gives up.
It's also been handy for monitoring my general fitness. Resting heart rate, steps, floors travelled, etc. I recommend the Garmin Fenix if you ever wanna try out a 'Smart watch' again: https://www.garmin.com/en-GB/p/641479