I'm a sucker for original cases, so I love the MUSHA cover. I generally print the red stripes only when the original retail cover is not available. The downside is, of course, lack of uniformity.
Unfortunately, Sega seemed to change their case art on a monthly basis. Early games had the large "Genesis" logo, then it was shrunk and "16 bit cartridge" was added. These logos could be found in various areas of the spine. Then, worst of all, Sega put the UPC codes on the spines of some games.
Things were a little more uniform when they switched to the red stripe artwork, but any sizable collection of original Genesis games (like I have) has the least amount of uniformity of any console.
Of course, third parties were also free to do pretty much whatever they wanted on their cases.