Shimano have loaded most of their best new tricks into the LX chainset and the result is unbeatable on up to date value.
Their 'so clever it's sorcery' Hollowtech hollow forged crank arm gives serious underfoot stiffness through the integrated axle. As long as you check the left arm clamp bolts regularly they're fine and the whole set up is a cinch to install or whip off for cleaning.
The alloy rings shift fast and smooth and the steel inner adds lifetime longevity for only a 60g overall weight penalty against XT. You'll need to replace the soft alloy middle ring pretty quick though (M510 steel ones at £8 are ideal) and the bottom brackets last much longer if the frame is properly faced by your bike shop before installation.