Honestly, its about the same product.
you could use expensive oils to impart flavor, but most like olive oil or peanut oil's burn easier at high temps.
The main benefit people will tell you is that they are more juicy, and this is mostly because people over cook their turkeys religiously. If you wait for that Red POS plastic pin to pop, all its telling you is that you've done it again. you made some dry turkey. Grats!
If you Roast your turkey at 350, covered with tin foil or a rosting bag... you should pull your turkey out of the oven when you get a reading of 145 at the thickest parts of the turkey ( the thigh is best for this )
Now, I know what you're thinking... BUT BUT I"LL DIE! I'll Poison my loved ones, and THey'LL DIE!
...
Pulling the turkey out of the oven at 145 degrees still leaves a carry over cooking time, and will carry to about 160. which is more then enough to kill any and all bacteria that may be present. and I would pull off the tin foil about 20 minuts before you get to 145 so that you can brown the skin the rest of the way.
NOW, this leaves you with a dirty roasting pan. and thats about it.
Deep frying, while exciting and quite the rage is quite dangerous. I don't care how safe you think it is, you still are cooking with a large pot of very hot oil. and should it never burst into flames, its still dangerous.
then, you have the mess. you get to clean off your burner when you spill oil all over it, and what ever you had the burner over at the time. which tends to get covered in oil.
then, you get to pack up the oil when it cools.. now I don't know about you, but when I've had a bunch of turkey the last thing I want to do is anything close to work.
I'm not saying its not a laugh, and a bit of fun to sit around a pot of boiling oil drinking a beer and thinking smelling turkey fumes... but its far less praticale and is not the better choice.