Praxis components are pretty good...i have their chain ring and makes for a strong and smooth shifting tarmac. The 105 brakes do not perform on the same level as the ultegra's...but unless you are flying down long steep hills there is no noticeable impact there. Roubaix is a very comfortable endurance bike that has always been the bike every other manufacturer measured against as the endurance standard for the industry. Bike is pretty stiff (pending which one you get) for an endurance bike and will get up and go when you stomp on it. Bike is also very stable and the geometry is excellent for staying seated and climbing. However, for that comfort and stability you do trade off some of the quick handling you find on race bikes and some other models...various models of endurance bikes range at different points on the stability-comfort-handling scale...you just have to pick the one that mixed it the way you like best. Nice bike with pretty decent component set...you will enjoy and despite what you hear Spec stands behind their bikes...I had an expert Roubaix that the clear coat peeled in a section and they replaced it with a flat black S-Works...they get two thumbs up from me.