Flew SE to Sanford in December and will be doing it again in March. I actually like Sanford better than MCO, mainly due to SFB's small size. It's clean, neat, and easy to rent a car. The only drawback is that it's much farther than MCO to WDW. The way I look at it is I'd rather drive from Sanford to WDW with a direct, nonstop flight from Allentown than drive the hour to/from Philly for a direct, nonstop flight between there and MCO.
In December, I took 417 to WDW and the I-4 route back to Sanford. The 417 route is easy to drive but the tolls were around $5 one way. I-4 can get really backed up around Orlando (I'm talking parking lot!). I drove I-4 east/north to Sanford between 4-5pm on a Sunday night and traffic was light to moderate. Last spring we drove to downtown Orlando on I-4 between 5-6pm on a weekday, and it was a rush hour/parking lot kinda thing. For us, I'll spend the extra money to avoid any potential headaches.
HTH!