I also have an old bushnell.It still works perfectly so I cannot see buying a smaller one.When it dies I will.I have found it to be very helpful in ranging objects around my tree stands.I am pretty competent with judging yardage on flat ground but depending upon the height of your stand or how the terrain around your stand is,the use of a rangefinder is an extra measure of certainty which add's to confidence at the time of the shot.
Even one of the rangefinders where you manually align the images inside the lens is not a bad idea,they are inexpensive and suitable for most tree stand hunting.