I didn't really know much about this airport, but your post made me curious. So I went to their web site, and there is a lot of info there.
http://www.orlandosanfordairport.com/index.htm
I want to point out a few things.
1. They say they are 35 minutes from WDW. How could that be, when MCO is 30 minutes? SFB is north west of Altamonte, which is almost an hours drive from WDW, even using the Greenway.
2. There are not a lot of carriers operating in and out of there, and there are not a lot of flights. So if you imss yours, or it is cancelled, you might be stranded.
3. Mears operates out of there, Tiffany does not. Happy does as well. My bet is that Mears does not offer shuttle service, but rather car/limo service. Itwouldn't be worth their while to do shuttle service from there. My guess is that because it is twice the distance, it would be at least 150% of the fare. Mears charges about $60 each way for a towncar from MCO, so my guess is that it would be about $90 or more each way from SFB.
4. They are not serviced by as many car rental places, limiting you options in discounts.
Anne