Trees are great when you have time pressure - you have the option to not twist any turrets. At long range with mild recoil cartridges like 6.5CM, you can get back on target after a shot and use the tree to measure your miss splash. If you shoot extreme long range and dial up all of your elevation, you may need to hold some remainder of elevation in your reticle - and a tree lets you still hold for wind. But some folks find them cluttered. YMMV, lots of reasonable people have different reticle preferences.