Why don't we scrap it entirely then, and instead have a first-run menu that prompts you for your graphics hardware (or, better, runs an automated benchmark and sets viewing range for once and all automatically
I take my words back on keeping it enabled by default, what I see is range finder is quite annoying when you have it on, when you walk it changes view distance too much back and forth and don't forget looking back with 240 causes sharp drop back to 35.
Automated benchmark could be nice, I support your idea (but it could be hard to implement). However, if it sets for you, say, 120 nodes (you have a good card), good luck playing single player with it because stutter will be just megahorrible.
Range finder is part of the problem. Low FPS could be bad optimization of MT in general. I'm not saying that it is bad everywhere, it tends to go much lower in crowded places with lots of user-placed blocks (and occlusion culing is per 16x16x16, which has limited effectiveness), if you go in wilderness FPS will be really good but with visible stuttering (another big problem for playability) while new chunks are generated. However, my tests seem to show there are indeed some regressions which slowed down the client.