Very easy to install if you have a flat area available. I put mine up near the grill on a Kubota... a little far away, but my eyesight is still good enough. (might have to move it closer later)
I don't watch it all the time, but I find it extremely useful when feeling a little tippy (tractor... not me). Due to my land, I spend a lot of time in the red zone, and I do believe that there have been times when I may have pushed the tractor further than I did if it had not been for the gauge telling me "no no, you shouldn't do that".
When I first got the tractor, I was much more timid, now I take it places I wouldn't have dreamed of taking it. That is where I find the tilt meter useful... it keeps me on the good side of that edge between brave and stupid.
Highly recommend it as an auxiliary piece of equipment... not as a replacement for common sense.