4200 vs. 5400 rpm int. hd: decision?

[Malcolm Hamilton]

Hello -
thanks to those who've weighed in on the subject of getting rid of the Dock.  I've found a little app on VersionTracker called 'dock-a-bye', which claims to do just this.  I'll try it when I get the chance and get back to the list.

Another question I'd love to revisit, regarding hard drives:  I have a 400MHz Titanium, whose 10GB int. drive is almost full.  I want to get a 40GB drive to replace it with - - should I get the 4200 rpm or 5400 rpm Travelstar?  I remember a discussion about this a while ago, but it quickly got too technical for me.  What's the bottom line, please?  Which is faster, more dependable?
If the 5400 is indeed faster, generally, what about specifically - - would my 400MHz processor be able to make use of the extra speed of the 5400 rpm?

Just in case it matters:  I use my Titanium for mostly regular things, but will shortly be doing some video editing on a G4 tower.  I'll probably want to take the odd project on the road with me - - this would involve using an ext. firewire drive, but the project files would have to be on my internal drive.  I know for video, faster is usually better, but I still don't know if the 5400 is faster generally, or, in the case of my 400MHz, specifically.

Thanks for any recommendations and advice!
Malcolm