Great question, Darkroomist! I have both but typically prefer the saddle stapler. The long reach stapler is a Pilot 412 I found in a thrift store while the saddle stapler came from Craigslist and is a Salco Rapid 106 dual head electric.
The Pilot is good for stapling together a single copy such as a first draft. As for the Salco, it isn’t always easy to get aligned on the booklet’s spine but it does save time when I have more than one zine to staple since it only takes one press of the foot-pedal to insert both staples simultaneously.