Many of the algorithms are based on the same principles but they are all different implementations. Blender is optimized for creating visually pleasing renderings, while Slicer is optimized for accurate data visualization and quantification. Therefore, in general you can expect that the two software provides slightly different results. If you create a mesh from an image and then process it in a mesh editor (Blender, MeshMixer, MeshLab, etc.), I would recommend to load back the results into Slicer to quickly verify that the edited mesh still accurately represents the source image.