07 and 08 are the only years that are imo truly pass years. The 07 was the introduction of the new motor with part of the tuning and an odd ball throttlebody. The 08 they added some more functionality like ABS and bigger tank if memory serves me, but small rear tire. Its not until 09 new frame, better ride and handling, new throttle by wire, larger tire.
103 and 110 use the same crank stroke although the crank was cheapened imo post 06 model motors. Its the bore size that makes the difference in the cubic inches of the motor. 03 has hemi heads if its a SE 103 the 110 is not hemi its more bath tub the sparkplug side of the chamber deviates / protrudes a little farther than a true bathtub shelf. 103 head has 1.90 intake and 1.623 exhaust. The 110 head is 2.080 intake and 1.623 exhaust
On the 110 new models the pistons are not typically at 0 deck they range more from .005 - .010 in the hole. The 103's were more 0 deck to .002 in the hole for the ones I have owned. 110 has compensator rattles the old style does not. Its said you can rectify this with the baker or gmr compusaver, but again something to consider.
03, 103 engine, 43mm throttlebody. 4.35 injectors, 94-95 cc heads hemi, old style chain tensions and cam plate
09 110 engine, abs, 50mm throttlebody, 3.91 injectors new style injector and cam tensions (hydraulic), new oil pump, crappier lifters up to 2013 cant speak past that, 94-95cc heads, new frame, better ride and handling. Hotter from the factory read leaner to meet EPA and no overlap in the cam in the 255 although is a torque monster and 7 more cubic inches.
If your after a bit more power and you want just reliability and getting rid of the heat and a proven combination on the 110 engine the 24d cam with headwork, air cleaner, good pipes and good tune will yield you that middle ground around 120 /120 without PMS. I have both versions of frame and the ride/handling imo is much better and for me a no brainer on the new style as the choice.