Sadly Connexion.org has shut down as of September 14th, 2011. If you are looking for HIV positive support I suggest http://www.poziam.com/
I reached out to connexion.org and an admin of the site replied to me with the below information. Personally. I have been a member of connexion.org for a long time now and compared to MH, A4A and numerous other sites I find this site to be top notch. They do not allow nude photo's, and they have a verification process whereby you can have your picture certified or "authenticated". They have instant message and video capabilities built into the site as well. You can post questions on their message boards and participate in one of their groups. You can also import your blog, and favorite music. You can taylor your profile to your liking. This site is the LGBT facebook of the internet. They have various groups you can join and one such group is a HIV positive support group.
If you are looking for quick sex then stick with MH, or A4A. If you are looking for quality conversation, and dating then I would prefer connexion.org. Though I cannot discount that no matter which site you meet from, as connexion say's "anything is possible when two people meet"
Message from connexion.org
Tim Gill, founder of Quark, Inc. and the Gill Foundation (advocates for LGBT equality) started Connexion in 2003. Connexion.org is a LGBT social networking site with over 175,000 active members worldwide. Members of Connexion.org enjoy access to a variety of features that help bring the gay community together. These include: daily news feeds, community message boards, calendars, instant messaging, email, party and social invites, and updates on philanthropic and LGBT community events. While not specifically a dating site, Connexion believes that anything is possible when two people chat. Membership is free.
With regard to HIV, Connexion took an innovative and unique approach to enabling users to self identify as HIV-positive. While most sites allow users to select negative or positive, Connexion felt that forcing users to choose leads to deception from people not ready to disclose their HIV status and a false sense of security that the person you are chatting with is actually negative. Instead, Connexion gave users the option to disclose that they are HIV positive if they choose to, but didn't give an option to state that you are negative. This was seen as a way to allow newly positive people to not have to lie about their status until they were ready to disclose it, without asking them to lie about being negative