The Beach Cruiser Mark II is, is the simplest terms, a more versatile edition of the original no-frills Beach Cruiser (be sure to give the original Beach Cruiser's description a read if you haven't yet). The Mark II is essentially the with-frills version. The rocker & outline are based largely off the original Beach Cruiser to provide a very similar top-notch wave catching and cruisey, easy riding longboard. While the original Beach Cruiser edges out the Mark II in top-end speed and stability, the Mark II offers a walkable, noserideable longboard with a more sensitive feel and a little more peppy turning radius & response. It's quite a versatile modern single fin longboard.
The similar outline & rocker as the original Beach Cruiser, now aptly named the Beach Cruiser Mark I, result in a very similar wave catching and easy, cruisey rides. The bottom contours & rails are the major differeniators. The Beach Cruiser Mark II is a multi-tool, so if you're looking for a more purebred noserider and noseriding is far-and-wide the most important aspect of your new longboard to you, check out the Rhythm. But the Mark II walks from tail-to-nose and noserides very well for those who definitively want that capability and more. The slightly wider, squashed-off tail shape adds more pep, energy and just a bit of pop to the turns off the tail.