Presses are an essential part of a weekly workout rotation. There are numerous variants of the press - whether it be an overhead press, a chest press, an incline press, or one of the many other types - the press is a hard workout to replace in terms of efficiency. The FlipSled version offers a mix of an incline press and an overhead press.
The Standing Press with a FlipSled is a perfect in-between of an overhead press and an incline press. Being between the two means that the Standing Press is both a chest and shoulder shredder. The FlipSled creates a hinge point for the lift on the ground, meaning you can lean in and put all of your power into it -- since it'll be braced on the ground. That leaning in allows the Standing Press to be more of an overhead press than a chest press, which introduces more work for the shoulders.