I would appreciate your thoughts on my dilemma. I currently own a 2006 Onix with Ultegra components and Shimano wheels (not sure of the model but perhaps WRH 560). It has been enjoyable but I have the upgrade itch sometimes. This is primarily due to a perceived lack of my effort being efficiently transfered to speed and performance. I am 6'3", 230 lbs and ride four days per week between 30 to 50 miles each outing. Should I purchase a better bike? Or would upgraded wheels and fork make a significant difference? If replacement is recommended, would the Orca or Opal be better for me?