In addition to what radio, vlad and 232 here said, I have checked out a LOT of systems and if you are clever, you can use the very unique features inside VLD to create any number of business models.
Also, who needs another e-harmony? Those users who want those kinds of features will go there and are hardly likely to come to you are they? I mean there is nothing new and you are positioning alongside a site with REALLY DEEP pockets.
An even more and less understood component about human relationships is WHY any 2 people are really together. Patent or not, I personally want to figure out things on my own and not be presented with pre-decided selections.
Example:
Lets say you were asked to define your interests. Are you 100% positive you will enter the same ones 1 month down the line if you did not remember the exact ones you entered the first time? Probably not. So much for patented stuff.
MSN YAHOO GMAIL integrations are unlikely to provide much success because these sites don't provide you the email address of the user. So what are you really getting? I don't care about these sites login with <any site here> features. I would like only people that are properly registered on my site to access the features and interact with the other members.
Also, how many users on the above sites, including facebook, have real accounts or are real people? There are a very large proportion of fake accounts.
So while all these are supposedly good ideas at attracting more members, they are in reality nothing even close. The ONLY way to build a site is ONE MEMBER AT A TIME, slowly and steadily. Yeah I know its hard work but then thats how it works. 
Look at the software and figure out unique models to attract members. Don't be just another site like eHarmony or the like. I am sure you will be more than happy with what you get from VLD.
As for customization and look and feel, you can get these from VLD quite cheaply but do try to get something unique and not fall into the trap of copying another site.
IMPORTANT: I am not an employee or spokesperson of VLD. So don't interpret this as a marketing pitch on their behalf.
Thanks.