Pros
Location - Charleston, SC is one of the coolest place to live in the country. Charming historic downtown and marvelous beaches and rivers as well. Nice mild year round temperature too. The company - at least the software department - is filled with very bright young people. Most of the management is pretty cool - down to earth, competent and fair. If you're idealistic, you can get a little bit of a warm fuzzy feeling knowing that your clients are non-profit agencies. Nice facilities and good work environment. Management expects results - so if you're a slacker you won't last long, but on the flip side, almost all of your coworkers are reliable and competent.
Cons
If you're not working at Blackbaud, there aren't many other employment options in the area. Pay is average at best. Merit increases only keep up with inflation. Only promotions get you a significant increase.