Your experiences in the site will be based on your circumstances and your expectations.

I used to hang out with girls fairly well in US and India so I guess I can give some balanced opinion. I have had mixed experiences. I got married to a girl from one of the websites. I wanted someone who was well rounded in life and had her own say and wasn't simply a parent's puppet. I was forced to seek a girl through matrimony sites as I worked in a small remote city in US with not many single indian girls. However, the first few girls I met on the website were a let down. 3 out of 4 girls that I met were on the site cos they got pushed out of their relationships that didn't lead to marriage (one's 6 year long steady boyfriend (from btech) died in car crash, another had a 6 year long boyfriend (from btech) from different state and his parents humiliated her parents when they asked permission for wedding so she had a very sad breakup and was looking for a guy according to her parents wishes to salvage her parents lost honor). Another girl first replied to me but then acted very defensive and silent which I later found was cos she had an on-off relationships with her long term ex-bf and couldn't make up her mind. These were the only girls I felt a connection with but as you can see they were searching for someone mostly because of bad circumstances forced them to. Even though I didn't mind their reasons, all of them eventually declined me because of reasons like mismatch of kundali/parents disapproval, ex-boyfriend trying to persuade the girl back etc. The remaining girls I found I didn't feel like connecting with them as they were there simply to fulfill parents desires- had no social or life experiences, were just blindly obeying whatever parents said, too nerdy, too boring, or too just too distant (me in US, they in India) .

After being in the site for more than an year I noticed a few trends: Given the sex ratio in India, the most well rounded girls who have good personalities, stable thoughts, good looking get already taken at a very early stage as they have many suitors (lots of single indian males in college, job in indian city, MS in US or job in US). So the girls you will come across in this site are those who for some reason did not find a suitor in their own circle. Those reasons would be primarily: She herself is very asocial/nerdy etc (which is ok, if you also have a similar orientation), they dated and all but for some weird reason dating didn't lead to marriage or, they are very successful and ambitious and stayed single for career based reasons (this is the most rare case).

Now I am very content with my marriage. The more expectations you have from your future wife, the more patient you will have to be to find one.