WD10EARS Benchmark

I recently installed a WD10EARS drive by cloning my old drive and then running the align utility.  I read on some Newegg reviews that it is not a good idea to run it as your OS drive.  I am running Windows 7 64-bit and I ran an HD Tune benchmark.  I am curious if this is acceptable for my OS drive, or should I only use this drive for data.