I'm a big fan of fitness trackers. I currently have the Garmin Vivoactive HR, but have tried a good amount of them. My favorite is actually the fitbit, because they have the most user friendly apps and pick up activities better then any watch I've tried. I've tried Fitbit HR, HR2, Blaze, Samsung Gear 2, Garmin, TomTom, and Pebble. Garmin is the only one that held up to my level of activity and had almost everything I need in a fitness tracker. Like I said the Fitbit has the best features, but they are so cheaply made. I haven't had one last me more then 2 months. As for the apps the best app to me is the Fitbit app followed by the Garmin. Plus Fitbit has a big community of people you can link up to.
I never run with a phone or headphones, so I can't use my phone for step tracking or activity tracking. The Garmin has easily been the most sturdy and held up to my level of vigorous activity.
I was originally of the belief that I didn't need a tracker at first. Then I decided to make the plunge and give one a shot because I wanted to know exactly how I active I really was, so I got the Fitbit HR. It was great until it broke a month later. Fitbit has a large community of people to compete with. Even though the group of people I was connected with wasn't large I made sure to at least beat them in my step counts. I grew to depend on my fitness tracker because more then anything it kept me honest. We can all say we are motivated and work out, but until you actually track it then you're really just cheating yourself. A fitness tracker will tell you when you are being lazy. The feature I like about my Garmin is the move feature(most have this feature) and how it sets your daily step goal based on your level of activity. Most watches you set a goal yourself. Usually 10000 steps is the default. You can do this with the Garmin, but I prefer the goals they set based on my activity. I hate when I don't hit my goals or my target goal starts going in the wrong direction. Makes me feel like I haven't been putting in the work. Especially those days when you are busy and don't have time to work out.
Fitness trackers give you a goal to reach and keep you honest more then anything. I hate people that post I'm at the gym when they only go once a week or if they do go everyday or often all they do is show up and don't really put in the work. This will keep you honest and show when you aren't putting the work. Also the Garmin is a lot more stingy with steps, activities, and heart rate then the Fitbit. TomTom has the best heart rate monitor. They work great when training for something.
Last thing is. They're all ugly to me, so look wasn't a big factor to me.