Should I put an SSD in my game machine?

Here's what I have:

Intel i2500 3.3 ghz quadcore cpu
a radeon hd 6850
8 gigs ram
a 600w corsair gs600 psu
windows 7 64bit ultimate

The reason I would get one is so games like Skyrim, Fallout: NV, the Stalker games (with the Complete mods), Crysis, GTA IV and other similar larger open world games have better performance in terms of loading times (like when new areas are entered).

with my current HDD (a four year old drive I salvaged from a broken laptop) certain games have a lot of stuttering most notably the ones listed above and even some older ones like the original witcher and the original Far Cry. whereas more recent games like Dead Space and Bioshock run silky.

My windows experience index (if its anything to go on) lists my hard disk performance at 4.8 and everything else is 7.5 (processor) to 7.8 (graphics and gaming graphics)

space isn't much of an issue as most my library is on steam so i can replace games i've finished as long as i can wait a couple hours.

my main interest is just in getting a new hard drive, but I read a couple places that maybe SSD was the way to go. I also read some places that it won't really matter. it's a matter of some controversy apparently

i don't think my current build can handle SATA III so i wanted to get a reasonably sized, reasonably priced SATA II SSD like this one: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I'm not looking to spend more than 150 and like i said space isn't too much of an issue nor am i looking for the most professional level of SSD.

Should i get one? SHould I get the Sandisk?
Do you think it will be a big improvement over my dinky laptop drive that I had to reformat and repair?