Go with SRAM Force. I would (I have Ultegra). You can replace the cassette when you purchase or later on --SRAM also has an 11-28 casssette -- and even put in their WiFli rear derailleur to use a 12-32 cassette. Plus, Force is lighter than Ultegra and the wheels are definitely an upgrade. Whether you miss the triple depends on the area where you ride and the type of triple you had (I switched from an 8 speed triple with a 12-23 to the compact w/ an 11-28 and, as a result, my lowest gear in the compact was lower than in the triple).