Depends; how soon do you want to ride? Buy the best beacon that you can OPERATE EFFECTIVELY and go have fun (safely, OK?) Don't forget to practice often and to check everybody's beacon every time you go out.
It doesn't matter what kind you have. As long as you know how to use it and feel confident, any of them will do. I have the original TRACKER and would like to update to the new one and keep my original as a spare. It's sickening how many people don't have/don't think they need one! The best part about the new TRACKER in my opinion compared to the original is the harness it comes with.