Well, on behalf of the MartialTalk staff, let me be the first to say welcome to the boards! Our Tai Chi forum is a little slow right now, but it is picking up as we increase our numbers!
Chen is difficult to explain, it uses principles such as open and close, circle and spiral. It is slow moving such is the nature of taiji but chen has explosive points where you release your energy in an explosion and then right back to empty. It is difficult to grasp and apply, but once you grasp it, it is very powerful to use. Its movements are sometimes referred to as looking like a corkscrew. Heavy focus on using the waist and in chen as opposed to say yang, your mind precedes your movements. What I mean is that your still finishing one move, but your mind or "intention" is already moving to the next technique. Its hard to explain. I hope that gives you a little insight into what it is about.
You background in Wing Tsun could possibly help as some of the principles will be similar, but if not careful it could also be a hindrance as somethings may seem awkward. I think your background will be a help more than a hindrance though, as some of the movements will be in your muscle memory already. Chen is not centerline though, so that may be a little different for you.
7sm