Apple Harddrive Upgrade Offer

I've just received an offer from Apple in HK for a harddrive upgrade for my 12' Rev A Powerbook (40Gb drive)

For HK$2000 (approx US$256) to have my harddrive upgraded to a 80Gb 5,400 rpm. The upgrade will be performed by Apple technicians and will be covered by my Apple Care plan

My questions on are the following issues:

1) Will there be much difference in speed compared to my current 40Gb?? Will I notice the extra rpms?? Will the extra capacity and buffer help speed things up overall (I'm currently using half my drive)??

2) Also will the new 80Gb drive generate any more heat than the 40Gb?? The Rev A's are already hot enough as they are.

3) And one last thing will the 80Gb draw more power from the battery and reduce the battery life??

Cheers

Thanks for the replies so far. So that knocks out heat and battery impact, I think ...

But still wondering if the performance improvement is going to be noticeable??? And is the upgrade price a good deal or is it not worth the price they're asking for???

BTW I received the offer via email from Apple HK. I presume they've got my email stored from having registered my Apple care plan

I'm not sure whether I'll get my 40Gb back, I presume so in order to allow people to back up clone their drives onto the new 80Gb.

The price includes installation at one of the Apple centers in HK.

Still curious as to whether I'll notice the speed difference??? There's not much use to spend another HK$2000 (approx US$256) on my Powerbook if there aren't any noticeable performance gains.

If I just needed extra storage it'd be cheaper to go and purchase an extra harddrive which would be much cheaper and quicker.