The NEC chipset version is a rebadged Optiarc AD7240 drive. It will scan but will not be as meaningful as the Mediatek.
If the drive has the Smart Erase feature, it will be a Mediatek. The outer box (if you get a retail drive) should also say something like iHAS524 A (you need to get the A variant, The Y variant is the NEC)
It's all a bit of a gamble without actually seeing the drive before purchase. There are also now a 'B' version of the x24 drives which as a different Mediatek chip, but still useful for scanning. The only thing I can suggest if purchasing online, is to get a retail boxed drive, then you should be able to determine which version the drive is without opening. Having said all that, I have yet to see any reference to a 524 drive NOT being a Mediatek drive.
There is one other way of getting one, and it is to get a Asus 24B1LT or a Plextor PX-880SA and crossflash.