I had the Magic Extra 300L with an OS .50SX on the business end. It flew like a champ and I really liked it but you know how this hobby is, you buy one and fly it then sell it to fund another project. Here is the info off of Model Techs homepage about the difference in the two planes.

"If you are like thousands of R/C aerobatic fliers who learned to fly "outside the box" with the Magic, you’re going to want to rock your world with the Magic Extra. It’s been modified from the Magic for optimal performance with a .46 two-stroke. We’ve reduced the wing area for better penetration on windy days, making it an overall faster plane. Its taller fuselage allows the Magic Extra to do more typically "Pattern" maneuvers better, such as knife edge maneuvers, and hesitation point rolls. Its new airframe design also gives better all-around tracking, for a more confidence inspiring performance. All this, and it still hovers like a friendly ghost! Like the Magic, the Magic Extra is an all wood ARF covered in real iron on film for easy repairs."