Geometry wise, top XC bikes continue to get slacker and add more travel. For example, the newest Scott Spark RC has 67 degree head angle (vs 69 on yours I think) and 120mm of travel in front and rear (vs 100 fork and 80 rear on yours?). Geometry is also typically designed for shorter stem and wider bars than were typically specced in 2011 (again using the Spark, it has 740 mm stock bars vs 620 mm stock on 2011 Scalpel 1) . Frames also tend to have more space for wider tires using 142 or 148 spacing in the rear. The Spark RC Pro for example comes stock with 2.4" tires. Otherwise, the difference is in upgradable components. Switching to 1x drive trains with clutched derailleurs removes weight and reduces chain drop. Also frees up space on bars for dropper post and suspension lockout switches. Along those lines, dropper posts are slowly becoming nearly standard even on XC bikes. Basically, this year's FS XC race bikes look a lot like what would have been called Trail bikes in 2011 with respect to slack head angles, wide tires and longer travel suspension. Whether you're missing out by not having any of that I can't say.