Actually ... I bought Perrie (TwistedGirl) one ... she loves Suicide Girls. And I thought, fuck it, I'll buy one too :P
So we both have accounts.
Ok, firstly... it's not a straight ahead softporn site... it's a massive community. It has private profiles that other members can speak to you with ... almost like MySpace, but 10 times better because it has less allowance to the user to fuck their profile up ... it has image albums per user too. When you look at a SG's images, it pops up a viewer that is also used when the normal members have images... quite nice.
Also, it's got discussion forums etc.
And of course, over 1000 girls.
Video... images... etc.
Some people dislike the concept behind it ... and until now, I was not really sure. But... I actually think it's great.
Now that I have real experience with it... It rules
And Perrie is happy too

So that's all that matters
