I have a this laptop and it works almost perfectly under Mavericks (Specs below). Just one problem, Sometimes when I close the lid, it does not sleep at all. This happens approximately 1 in 5 occasions. On the other 4 in 5 occasions, it will sleep just fine. I can tell that it is sleeping because it disappears from the network when it sleeps properly. I also always check any assertions (pmset -g assertions) to ensure that no background services are preventing sleep.
When I use the Apple Logo->Sleep from Finder and close the lid, It will sleep just fine every time and I can safely close the lid once the keyboard backlight turns off.
-Intel i7 4510U
-Intel HD 4400 (1920x1080 kexts from 10.9.1 to enable HDMI)
-ALC283 Audio (small issue with headphone audio)
-Replaced Intel Dual Band 7260-N with Broadcom BCM94352HMB.
Have any of you guys experienced this issue before? Is the away (maybe a small App) that will force sleep every time I close the lid. I have tried a few DSDT patches (thanks Rehabman) but no success yet.