http://www.atotchat.org/~montavis/dmo/comp/raptorlong.jpg - Raptor 74GB ADFD
Close enough to the 36 GB? Yea I think so.
Also, I believe a better explanation of platters is that they are two sided. The maximum platter size for today's ADFD Raptors is 74GB (75, whatever). So when they make the 36.7 GB Raptor, its just a single sided platter (half the platter). Now some people state that this is expensive to manufacture, and it probably is, but chances are WD does make purely single sided drives. Some 37GB raptors must also be bad 74GB raptors, and so they're shortstroked. Perhaps parts of each side are disabled. In such a case, you would have the fastest damn Raptor in the world, but who knows if they disable one side fully or parts of both sides to attain 37GB.
I don't have a 150GB ADFD Raptor benchmark on me because all my HDTach results are saved on my aging 160GB Hitachi which is on the verge of death (I need to do some quick backups). Also, the 150GB Raptor is not mine, but my friend's so I would have to borrow that once again to do a 74 vs 150gb test, but I'll tell you that the STR test shows my 74GB is faster by ~0.5 MB or so.
http://www.atotchat.org/~montavis/dmo/comp/raptorvs7200.9.jpg - Raptor vs my 7200.9 250GB drive.
If you really want results, please just go post on StorageForums or OCForums, or whatever you want... Ask them if they have benches. I'm sure those SR freaks would do it because they bench every damn variant of the 7200.10.
Ok, and either folks here or on SR pointed me to this link:
http://tweakers.net/reviews/621
74GB ADFD wins CONSISTENTLY. There. That could be a shortstroked 150gb, but I can assure you this means there are 74GB drives that are faster than the 150gb version.
Now this just depends whether you get a shortstroked drive or not. Some people got short stroked Seagate 7200.10s. Some didn't. It's just luck.