I have not found that to be the case for me. I have a Dell Studio 15" with 3GB of RAM, 320GB 5400rpm HDD, 2.4GHZ P8600 and 512MB ATI Radeon graphics card running windows 7 Ultimate 64bit and it can do even the most basic tasks lightning quick. Opens firefox in under 1 second, Word in less. To top it all off I only have 20GB HDD space left so even with my HDD nearly maxed out it is still snappy. I have tried a 7200rpm drive in my laptop and really didn't notice anything more then a slight degradation in battery life. I think your main issue sadly is the i3 processor, for gaming or even laptop use in general I personally wouldn't go under i5 unless I was looking at a netbook.
A 7200rpm drive may make a difference but I don't think it would be significantly more then then the 5400rpm drive. The Seagate Momentus (hybrid drive) would certainly speed things up, being faster than the WD Raptors and all.
It looks like a pretty good laptop though. I like the hybrid graphics feature and the fact that you can customize the keyboard colours, I actually had a play with one of these the other day, sadly the Australian price is $1,600 (costing $400 then my dell did 12 months ago). It's a real shame that it doesn't come with an optical drive.