From H-D specs pages:
Seat Height, Unladen/Laden: SG - 27.3"/26.3" SESG - 27.9"/26.5"
Ground Clearance: SG - 4.7" SESG - 5.1"
Front Tire: SG - 130/70B18 SESG - 130/70B18 (same)
Rear Tire: SG - 180/65B16 SESG - 180/55B18 (18 versus 16 inch)
Looks like the flexible SESG seat sags a lot more than the stock seat, if you look at the differences for laden and unladen seat heights. That correlates with all the problems folks have had with the SESG seat and how it fits after it sags in the middle.
The rear wheel and tire combinations result in approximately .6" more height at the rear axle on the SESG, and approximately .4" more ground clearance measured at the frame.
The rear suspension height is supposedly the same on the two models, even though the SESG has the new hydraulically adjusted shocks instead of the air shocks. Not totally certain on the front suspension, since there is a lowering kit in the catalog that says it fits the FLHX, but not the FLHXSE. It doesn't say it's already stock on the FLHXSE, which would be the normal way they would indicate if an accessory part was standard on a SE bike. It's possible they don't sell it for the SE because the rear of the bike is higher due to the 18" tire and wheel, and lowering the front further would adversely affect rake and trail, but I can't say for certain. So that one I'll have to leave to someone who has the actual parts books to figure out.
Jerry