I do think the pace is accurate and you can keep an eye on it and see your pace whenever you like. It's not flickering around changing all the time, so it must update the pace at certain time/distance intervals, showing how fast you'r currently running, but I'm fairly sure it's accurate.
Having the build in GPS is great too, not having to carry a phone and also having built in heart rate monitor.
When you have it in running mode, there are two data screens you can switch between to look at as you run.
The first screen shows distance, time you've been running and pace
The second screen displays heart rate zone, current heart rate and calories burned. I've never really flicked over to look at this one during a run, as I tend to just like to know pace and distance.
You can set it up with a virtual pacer, meaning you choose a pace, such as a 9 min mile, and it will tell you if you are on pace, fall behind pace or are ahead of pace. It's very useful.
You can also set a distance alert if you want, so it tells you when each mile is done.
I've not used this yet but you can set up heart rate alerts too.
You can use the watch to set up an interval work out.
Once your run is completed and you've saved the session, there's a nice breakdown of your run actually on the watch which is good as I think a lot of watches you need to wait until the data is on the app. I then just syc it with my phone and you can see the info on the garmin app and it also goes up to strava.
The garmin app is brilliant too. You can link this to my fitness pal as well.
I didn't want to spend a huge amount and when I was researching it I found that this watch had the most features for the money. Also some others were more like activity trackers where this one is definitely geared up for running more so than anything else.
Hope this helps!!