Laptop HD Speeds ?

Possibly power consumption/battery life issues.

Don't forget cost and heat as well.

Sound levels, power savings, some reliability, probably last is cost.

And it's only taken three of us to nail all the issues.

I was looking to upgrade my HD,,,,,,,,7200rpm, Hitachi looks nice

Hitachi is a good laptop brand. 7200 vs 5400 will get you a noticable increase in speed, but also will make it a bit louder. Make sure the drive you get will match the hight limit of your laptop, some drives are taller than others. Also if you have a netbook or a small laptop, make sure the thermal dissipation will work for the hotter drive. You can usually check the vendor site, if they offer a 7200 rpm drive as an option for your model, you will be OK with upgrading. If not, you may be taking a small risk (very small, but good to note at least before you take the plunge).