think if you go lower you'll be putting alot more pressure on you wrists, especially if you're doing plenty of freeway riding.
if wind is your nag maybe try increasing your top hat, mine made a really big difference to wind in every position, I dont need to lay on the tank to get any less wind resistance than a normal tuck.
Obviously when it comes to wind the TT is the better choice to the S4, but an added screen is a nice between
