WD is way over rated imo, i have had more number of WDs failing on me compared to seagate and WD green has speeds equivalent to 7200.10 series from barracuda.
7200.12 series has ~100MBps Average transfer speed.
warranty is like once or twice in 5yr 'if it at all happens' and if you can take that burden then you shall not compromise on the performance difference..

although for a person without sata slot on board, its advisable to get external hdd or internal + hdd doc