The life of the contacts in the relay that controls this motor may be shortened by going to a higher power motor.
The 1/2 hp motor will draw ~6.1x(0.5/0.3)= 10A so the wires that were carrying 6A will now have a temp. rise above ambient 3x higher than before so the life of the wire insulation may be shortened.
You may not notice either of these effects.