First,
there is no whine in my MacBook. My MacBook is very quiet. My Mac Mini G4 1.5GHz is louder than my MacBook.
As for heat, the bottom gets pretty warm from the processor (2.0GHz model), but even with shorts on I can put the thing in my lap (bare legs) and it is tolerable. I think if this were aluminum I couldn't do that, so that is one benefit of the plastic enclosure.
NOW, ON TO HARD DRIVE INSTALL.
These photos below show just how easy it is to install the drive. The hard drive is
NOT a user installable part, but the memory is (per the User's Guide). The User's guide tells how to remove the L-bracket that is covering the memory (and hard drive area). Once the L-bracket is removed, then the hard drive is exposed as well as the memory. The two memory slots are to the right/top of the battery compartment in my photos -- the little levers sticking out are how you release the memory if you want to upgrade. The hard drive has a white tab attached to the drive caddy. The tab is tucked underneath the drive (MacBook is upside down, and so is the drive, so the HD normally sits top-side up during use).
Simply pull out the HD using the tab, and viola, you can use a T-8 driver to remove the 4 hard drive screws, put the thin drive caddy on your new drive, tighten the screws, and you are ready to go. Very, very simple. Just make sure to put the drive in the same way you took it out, top side down.
Click thumbnails for larger image.
Second photo I forced the flash, which is why it looks better. Let me know if you have other questions or want more photos.