Rode the 07 Yamaha sleds last winter at a demo and fell in love. Now that I have an income I'm considering buying a used or holdover 06 Apex. My question is: what are the differences between the different models? I know the RTX has the Fox Float shocks. I also know that the ER has the rear suspension that can be adjusted on the fly. I really like that idea and was wondering if only the ER had it or if the other models did too. What are the other main differences? Thanks for the help and hopefully I can find one that fits me before the snow flies!