I reckon there would be, especially with Rosetta. I'm not totally up with how it works but I know it loves RAM and if it had to page things in and out of the HDD it would be preferable to run a faster disk.
It's a toss up really, outright speed or extra capacity. I figure you can always get a really good external drive and as such I'd put a 7200rpm drive in - the MacBook Pro is meant to be the best so I'd put the quickest you can get into it.
Stick the quickest you can in it, the extra 20 gig is nowt if your serious about storage, plus the difference in power required for a 7200 is *tiny*, will have no serious impact on your MBP's battery life.
well if you are putting that much down for basically the top of the range machine, what will the bit extra be to get a faster hdd. if you dont get it ou will regret it! i regret not getting the faster hdd when i got my pb (mainly bacause i didnt know what the extra speed would add!)
I got a 7200rpm drive in the last rev 15" G4 Powerbook and the drive was LOUD! I could hear basically every read/write that was preformed. I eventually returned it because of the noisy HD and the horizontal lines issue (mostly because of the lines issue, I could have lived with the noisy HD).