I had a Retul done through my job (lucky), and I was really impressed. I've been riding about 20 years, and pretty much have my fit dialed in, but since I was offered the Retul, I gave it a shot. It did show that my saddle position was spot on (thank you very much), but my left knee was 'kicking out' a bit when got low on the bike. The guy doing the fit called it before I even got on the bike... I hunch too low when in the drops or low on the hoods. When I get low my pelvis interferes with the upstroke of my leg. So the solution was to come up just a bit with the brake hoods, and roll the bars down a bit (so the effective reach in the drops and the hoods was shortened). Also a bit of a bad habit on my part was to hunch my back. So, with the correction in the bars, and a bit of working on keeping my back straight, the knee is tracking straight and I'm actually making more power. So, the super high tech stuff is definitely effective. But all of the "low tech" fits I've done have also been effective regarding saddle position.