I'm looking into buying a Canon 50D that comes with 28-138mm IS lens. I currently have a Rebel xsi that has a 18-55mm. Do you think it would be wise to purchase the 50D and sell my xsi or is there not much difference.??? Also with the 50D & 28-138mm IS lens. Will that have much distortion as my XSi & 18-55mm lens??? Because I love that distortion look. PLEASE HELP. IM NOT SURE IF IT'S WORTH THE HASSEL OF SPENDING THE MONEY ON THE 50D and TRYING TO SELL MY XSI. :-/ confused. THANKS SO MUCH.