Why would I want a laparoscopic splenectomy instead of an open one?

Many reasons. Laparascopic spleen surgery results, if successful, with less pain, smaller incision, less hospital time and faster return to work.
Smaller Scar. Minimally invasive surgery will leave you with a much smaller scar, less pain, a faster recovery, and, may reduce the complications associated with prolonged convalescance in the hospital. Be sure to seek out a surgeon with advanced laparoscopic training, experienced in this procedure.