Picking a hard drive

I've come into a bit of money, so I feel it's time to finally upgrade my eight-year-old Seagate Barracuda 200GB drive. There are two 1TB drives within my budget - another Seagate Barrucuda, or a Western Digital Caviar Green drive. I'm only running SATA II, however I'm relatively certain that a mechanical drive can't max it out. I'm aware that the Green drive is a 5400RPM drive, but would you guys say it's worth the sacrifice in speed for less noise, power consumption and as far as I can tell, longer lifespan? 

seagate and call it a day!

+1000 this guy has is priorities straight!!