I've had one for a couple of years. I was between getting a mid-range Hotas like the Saitek X52 or getting a TrackIR, went with the latter and didn't regret it.
That being said, while it's easier to keep your eyes where you want it takes some getting used to. Plus, it won't make you a better pilot, just a better informed one. I found out i still sucked at scissors after getting a TrackIR just like i did before getting one
Having flown without one for many years i think it's entirely possible to fly and do reasonably well, it just takes more effort to do so.