Floating desktop environments like Gnome and KDE on the other hand feel like bad OS X copies and definitely are not on of Linux' strengths.
On hardware: You have to watch out what you buy. If you just want to run the most bleeding edge hardware then there will probably be some sort of driver fuckup with linux. Though you might not be able to avoid the mentioned Optimus technology in a months :(
On suspend/resume: I'm running Linux on an 2009 Macbook Pro and the suspend/resume works like a charm. It needs a few seconds more than OS X to wake up completely but it works. So I guess this is hardware dependent too and not a general problem with lx.
Desktop software: If you want to run typical desktop software like Office, Video Editing, etc. Then yeah - Linux is probably the wrong OS for you. I'm in the lucky position to be able to do most of my work in terminals and VIM and for that there's nothing better than a Linux box with a tiling WM.
I'd say Linux is not a general purpose desktop OS in its current state. But there are use cases where linux rocks. (Even on the desktop.)