Whoa turns out people have been interested in this...! Calm down, everyone, the guide is coming soon.
Sending this from my G500 on OS X with a new BCM943225 Wi-Fi+BT3.0 card.
New notes in no specific order:
-Wi-Fi: The kext patching and SSDT methods didn't work for me to enable the Wi-Fi card. Apparently you need an AMI bios to use the DSDT method, which doesn't apply to us, so I used the enabler kext method which worked instantly. Bluetooth worked right out of the box. The BIOS flashing process (since Lenovos have a whitelist which won't allow you to boot with another mPCIe card) is very straightforward, took me 2 minutes at most. You need Windows to backup your BIOS and install FreeDOS to a usb flash drive. Ask politely in bios-mods and you shall receive, then thank them nicely. If you get error 28, PDR Region does not exist, GBE Region does not exist, just hit enter anyway.
-Audio: As for now, using VoodooHDA 2.8.1, the line-in/ext. mic part of the combined in/out 3.5mm jack outputs pure noise. Having Clover auto-patch AppleHDA or using other VoodooHDA versions hasn't been tested. If anybody here manages to make a good AppleHDA patch for the CX20757 it will be very welcomed. I personally don't see the use on either using an input device or an output device, only one at a time, so it's not a deal breaker for me. I'd rather use an audio interface or my iMac.
-Comparison to a real Mac model: The MacBook Air 11" 2012 model lacks audio input and optical out just as our hack. It has pretty similar specs to the G500, from screen resolution to integrated video and even CPU if you choose the i5 version, with the lack of Thunderbolt and size/weight compensated by the extra USB ports, optical drive, ethernet, HDMI out, and upgradeability of the G500.
-Battery: If the battery report on Windows is correct, this battery/computer doesn't even log the cycles. It shows "--". So maybe it is not even possible to show it under OS X. This computer's battery, combined with Mavericks' power saving features, give us even longer battery life than advertised for stock Windows! Especially if you're doing something like streaming iTunes Radio through AirPlay, you could get maybe 6 hours or more with the lid closed.
-Random reboots: Yesterday the machine rebooted instantly on wake up for some strange reason. An hypotheses is that it happens after very long sleep sessions, how long? I'm not sure. Sleep seems to work perfectly the rest of the time (i.e. <~30 minute sleep periods). Workarounds: If you're doing something very important why not rather save whatever you're doing and turn it off, or deactivate sleep using InsomniaX? Since 10.7 you can get every window back after shutting it down, try it.
-Card reader: A very complicated and not-so-worth-it workaround to use the internal card reader while booting on OS X is to boot your Windows partition using Parallels, mount the card reader to the virtual machine, then copy whatever data you need to your OS X partition or vice versa. Mounting the Windows card reader partition to OS X won't allow you to open anything unless it's already open in Windows for some reason.