Over the years, I have bought many bikes and each time I was fit on one, the fitter came up with slightly different seat heights, reach angles, etc. I always felt comfortable after we were finished because I am quite flexible but I always wondered if I would be better off if this or that changed my position. I knew that getting fit on a bike was part art and part science but then I heard about Retul. With their system, art still plays a role but it's mostly science. Long story short, after the fitting my saddle height was almost 30 mm higher than any fitter ever had me and as a result, I can make 25 more watts of average power over 20 minutes based on my CycleOps trainer. I highly suggest looking on the internet to learn more about it than what I can write here. Racers at the highest level use it but it isn't only for them. It will help anyone who rides a bike get the most out of their bodies and keep your joints from having issues over the long term. Also, make sure your Retul location has a Zin wand. After they set up the bike, they use this wand to measure the bike down to a third of a millimeter. This makes reproducing the data a snap if you change out a component or want to set up another bike. It will also help you in deciding if a frame you are looking at buying sets up well for you. They email you all the data if you request it and you could send it to Moots for example and they could tell you if you need a custom frame or not. The mystery of building a frame to work for you is removed. On a side note, a cross country mountain bike seating position is very similar to a road bike but they shoot for a 5 degree higher back angle and they generally push the saddle further back by an additional 5 mm or so. Cost is about $250.