Sin2beta isnt the only Sega guy on here!
As far as the game goes, its exactly the same except for the barcode thing. The whole barcode situation with the 4 Master system games (the other two are Spider man and Strider) needs to get removed from the thought of everyone. Barcodes are simply a way for the store computer system to recognize what the item is and to gather its price for the register. They arent even the same across most stores themselves. If you buy a new game from Best buy and try to take it to Wal-Mart and return it for cash, chances are the system will not recognize that barcode. So does that mean that in order to collect US games, that we should have to go buy a copy from Wal-Mart, Target, Best Buy, Gamestop, Amazon, etc just to have all the copies? I have been preaching against the stupid SMS barcode for months and it eventually led to me taking over the NTSC Master system list on Sega Age with updated qualifications.
If you were thinking about buying the game to play it, I wouldnt go the SMS route. Sonic's Genesis collection on the PS3 is $20 new on literally every shelf of game retailers now.
http://en.wikipedia.org/wiki/Sonic%27s_Ultimate_Genesis_Collection . Its a great game to play. I thoroughly enjoyed it more than Legend of Zelda itself.