I've actually bought both an Intel 520 240GB and Crucial M4 256GB!
I've not started building the system yet, but I'll use the Intel 520 for OS + progs and some games, and the M4 for more games.
Initially I ordered one 60GB and one 120GB Intel, but cancelled the 120GB for a 256GB M4 as I found out that the M4 was good as well and more GB for the buck.
Intel's drives should be more reliable as well as faster, but the M4 has proves it self for a long time.
Then all of a sudden the big Intel 520's dropped almost 50% a week ago, so I ended up cancelling the 60GB order for a 240GB Intel as well..
Had I not bought the M4 from another supplier already when the Intel prices fell, I would prolly had changed my other order to 2 Intel's instead.
Parts lying and waiting for me (my ARMA III hope):
MB: Maximus V Extreme
CPU: i7-3770K (Prolimatech Genesis cooler)
RAM: Kingston HyperX Genesis 2133, 4x4GB
VGA: ASUS GTX 690
Sound: Xonar Phoebus (Razer Tiamat Elite, true 7.1 headset)
PSU: Antec High Current Gamer 900W
Main SSD drive: Intel 520 240GB
OS: Windows 7 Premium 64-bit
Case: Corsair Vengeance C70, Black (to be modified, especially HDD tray air slots), with loads of fans & DEMCiflex dust filters!