I referee different age groups as well as summer tournaments, so the verstality is great. The main feature is the ability to stop the clock on the stop watch while still leaving the elapsed time running, when you couple this with the alert feature (which you set to vibrate or beep at the end of normal time) then you have everything you need for a regular match.
There's another feature which is intended to be used for training, where you can setup 9 intervals of differing lengths, again you get the vibrate or beep at the end of the interval and then it moves to the next. It's intended for training- so you jog for 5 mins and sprint for 1 etc; and it works well for that, but equally you can set in advance for phases of your match to remind you to re-think your strategy etc. You can use this at the same time as the other alarms and timers.
My only gripes is that sometimes it's not easy to see that you've zeroed the stopwatch ready for the start of the 2nd half, and it would be nice to have a total elapsed time for both halves function.
Overall it does exactly the job I need it for.