I would say 4 as well. Could even be older. Looks heavier than 150 as well. We've killed two 4+ year olds this year that have been our biggest bidy weight deer in years. One was 210 live weight and the other was 150 field dressed with his head and shoulders still on the ground. I figured the bumper acorn crop we had would have all the deer fat as ever.
Congrats to the hunter that got him.