The 11-speed XT derailleur is in terms of function and switching performance of the XTR rear derailleur in nothing, only the slightly higher weight could be considered a minus point.
Like the big brother of Shimano's top series, it delivers fast and smooth shifts. With the revised Shadow + technology, the bias of the chain can be adjusted via a small lever on the rear derailleur in two stages. So you can decide whether the chain should run quietly with less chain tension, or taut for rough lenght must be tightened.
The Shadow construction reduces the lateral projection of the rear derailleur and thus reduces the risk of hanging with the rear derailleur on sticks and stones. The used scraper rolls with sealed bearings, run very clean and offer a long life!