No downside to Grady drive woth mentioning except more expensive than motor on transom model.
Full height transom is better protected from water intrusion vs. motor on transon.
Grady Drive metal material same as motor's metal, treat exactly same way. If you don't - you will have problems, same goes for motor.
Massive room at transom with Drive for rigging, batts, pumps, fish wells etc.
Drive models most popular vs motors on transom, any Grady model ever offered with a choice.
Gulfstream drives came in two versions, single and twins.
Easier fishing access vs, eurotransom, since motor is closer to coming pad at stern.i.e stern is fully fishable not just cormers. Acces not as good as motor on transom.
Quieter boat since motor power head is outside full transom, head partially blocked by it.
Safer for young kids and dogs from being swept out stern on motor on transom cutout.
Some say safer from following seas breaking waves from drowning boat.
