Momentus XT vs. Raptor vs. SSD

I've found a couple threads and a couple articles on the internet, but nothing exactly what I'm looking for. What I want to know is the hierarchy of the above-mentioned drives: Momentus XT, Raptor, SSDs. I know SSDs are far and away the best, but I don't know how to rank the first two. These are being considered for the OS drive, as well.

What I would like is for someone to lend their knowledge to me and the rest of the commune. I don't want opinion, either, I want facts. Benchmarks, tests, what have you. Also, I'm not considering RAID arrays for this test. I want a single SSD vs. a single Momentus XT vs. a single Raptor drive. Or mainly a Momentus XT vs. a Raptor. I merely mention the SSD because I hope to get a couple of its benchmarks in here to help for comparison's sake.

A couple things to consider: I live in Canada right now, and as it stands, a 150GB Raptor is just north of $220 and a Momentus XT is 500GB is about $150, so there are savings to be had, but performance costs money so cost only becomes an issue if there's no difference in performance.

What I've got so far:

I've got some info on the Momentus XT vs. a regular 7200rpm Momentus in front of me (care of MaximumPC), and the only difference I see between the two are the random access reads (1.9ms vs. 16.5ms, in the XT's favour), a 175.9mb/s vs. a 133.4mb/s burst read and a better random access write time at 1.2ms vs. 16.5ms. All these benefit the XT. The average read and write time differences are negligible, though. If I were to purchase a 250GB XT with the purpose of installing the OS, program files and game files, what are the chances of it boosting things? I know it's got 4GB of NAND, but does that run out if I start the computer and run Photoshop and a couple different games? That's my main concern. How much can I run before it starts forgetting about my OS files? Or is that possible?

I've got plenty of benchmarks on SSD's that perhaps I'll post in a bit for comparison's sake, but I'm looking for some comparable info on the Raptor.

Thanks OutOfBalance.

I notice the article (at a quick glance) mentions the 600GB Raptor. I was thinking more along the lines of the 150GB. Are there any big differences? I'm just stepping out, but when I get back I'll look into it more unless someone beats me to it.

I don't understand how a 7200rpm Samsung drive can be faster than any other 7200rpm hard drive, at least significantly. And if short stroking a Samsung is supposed to be faster than a Raptor, why couldn't I short stroke any other 7200rpm?

And again, RAID is not an option.

Do platters equal partitions? (still a little new to short-stroking and the lingo, sorry)

And what makes the Samsung F3 so much better than any other HDD?

After much scouring of the internets, here's what I've come up:

I couldn't find anything substantial for the latest model of the 150GB Raptor, notably the WD1500HLFS, so I went with old RaptorX benchmarks, or at least ones I could find.

I also went with the basic benchmarks and the ones I thought would correlate best with OS drive characteristics.

AVERAGE WRITE SPEEDS (MB/s)
Seagate Momentus 7200.4 - 82.0
WD 150GB RaptorX - 63.0
Seagate Momentus XT - 81.9
WD 300GB Velociraptor - 100.9
OCZ Vertex II - 221.9

AVERAGE READ SPEEDS (MB/s)
Seagate Momentus 7200.4 - 83.7
WD 150GB RaptorX - 65.0
Seagate Momentus XT - 82.5
WD 300GB Velociraptor - 99.9
OCZ Vertex II - 196.3

BURST READ (MB/s)
Seagate Momentus 7200.4 - 133.4
WD 150GB RaptorX - 139.0
Seagate Momentus XT - 175.9
WD 300GB Velociraptor - 210.0
OCZ Vertex II - 228.0

RANDOM ACCESS READ (ms)
Seagate Momentus 7200.4 - 16.5
WD 150GB RaptorX - 8.1
Seagate Momentus XT -1.9
WD 300GB Velociraptor - 7.2
OCZ Vertex II - 0.1

CONCLUSION
Now, the link OutOfBalance left compared the XT to the 600GB Velociraptor, which is also 6GB/s compatible. It doesn't say which is used, but right away the XT beats the 600GB Raptor in load times. And since the 600GB blows out the 300GB (even at 3GB/s), the XT is looking good there.

The 150GB Raptor benchmarks suck, even compared to a typical 7200rpm. The only thing better was the burst read and, more noticeably, the random access read. Other than that, the Momentus XT cleaned the 150.

I had a little price mishap, as the Raptor is like $40 cheaper than I originally believed. So basically the 150GB Raptor is only about $40 more than a 500GB XT.

The only thing I can discern from reading reviews is that the Raptor is just a fast hard drive. Compare it to... one of the Klitschko brothers (boxing). And the XT is hard drive that picks its spots and adapts, so compare it to Butterbean (a fat boxer). Butterbean hits like a ton of bricks and that's more than a lot of boxers can say, but he just can't deliver a full-out boxing effort all-day long. This is comparing the Raptor 300GB to the XT. Since I don't have any good numbers on the neer 150GB, I can't say much.

My main concern is the NAND on the XT. At only 4GB, how much can it really remember? I've read about increasingly faster sequential read times, which is good I suppose, but what if I only boot my computer up once every couple days? I don't want that speed to be hanging in limbo, I want it for loading programs and games. But then again I can't say how adaptive its memory is, as in how quickly will it adapt.

Right now, for boot drives I'm gonna say its like this:

SSD > XT > Raptor***

But I'm gonna asterisk it, because who knows how much is too much to really throw this thing off. I'm not saying it's unknown, I'm saying I personally don't know, so if someone does, please, enlighten me.

As for everyday speed:

SSD > Raptor > XT

This is purely on the grounds of the limited nature of the XT's quickness.

This is what I've found so far. If anyone has anything at all -- comments, questions, 150GB benchmarks for the love of GOD -- I'm trying to learn as much as I can, so pour it on.