Beyer dynamic DT250 and DT150 are very neutral cans designed for studio use. Upgrading to hifi headphones will deviate away from a neutral sound. HD650's look quite good but HD600's are flatter. Do you need isolation from external noise and low leakage? (as both the cans you have picked are open backed)
It can be subjective sometimes. We all pick up different things . I've got senn 598 /600 /700 , and I find the 598 better than the 600's . But my 700's are my main play
Go into a local main dealer if you have one and try a few out