- Strip Merger has several advantages over the default ‘Bake Action’. It’s really just a more developed version of it, taking the concept and adding some quality of life improvements. - Strip Merger only bakes the NLA Strips that are selected, automatically finds the range of frames required and attempts the put the newly ‘baked’ strip in a logical spot to replace the strips that have been baked. - By default, you can’t easily choose which Strips to bake and which not to. You have to specify the Start and End frame manually every time and the new ‘baked’ strip is just lumped in a new action strip. - NLA Merger also bakes non-locomotion information, allowing for many other animated object properties to be stashed, while ‘Bake Action’ only preserves location, rotation and scale.

NLA Strip Merger uses the default Blender-baking operator, so speeds are not any different. What makes things faster is the saved time from merging strips and baking any valid animation data from the object and its armature (bones), that's otherwise unattainable, at least in any simple way.