Was browsing and saw this thread, thought I'd chime in with my .02.
I recently.. (couple months ago), purchased a raptor in my quest to completely replace/upgrade all the drives in my system... it's a long story, don't wanna go into details here. Anyways, it's my new boot drive, and I'm extremely pleased with it... I need more!
(three more, to be exact)
Idle noise: It's nearly inaudible when idling, especially if you go to any trouble to muffle it... my case has some soft rubber mounts for the 3.5 cages, which fit between the drive and the cage... the screws mount through the holes, so it's not a perfect system, but... mounted with care, using the 'default' setup that comes with the case... you basically can't hear it. Mind you, the noise floor for my case includes one of those really noisy MSI northbridge fans, but I try to accomodate that in my judgement of the idle noise.
Seek noise: I like the seek noise... best way I can describe it.. it's more of a 'throaty rumble' than an actually defined click or anything. I find it a very pleasant sound, and it really doesnt intrude, unless you do something that causes a lot of seeks... I like it because it lets me know the drive is there, without distracting me from what I'm doing.
Is it totally silent? No... but it is very quiet, and the seeks are not irritating, at least not to me.
Oh, as far as heat goes. When I first bought the drive, I had it laying on some foam on top of the case, for the initial format/surface test... and it did get quite warm. However, mounted in the front of my case, even when I didnt have the front fans running, but with _minimal_ airflow over the drive, it.. well, it's slightly warm to the touch, but then almost all drives will be. It is not hot by any means, as long as you maintain that minimal airflow. By contrast, I still own 4 IBM 75 GXP 'Deathstars'... the reason for my intended replacement of all hard drives, and they are significantly hotter running, and MUCH noisier, even at idle. You can hear them on the other end of the house, if I open all the doors and it's not too noisy outside. When the A/C kicks in it drowns it out though