Rock River Arms has a pretty decent reputation for being reliable and consistent: a reasonably quality product at what was - about two months ago - considered to be a moderate price. (Currently it seems the sky is the limit - its worth a lot more today than it was two months ago.....)
If it works for you, then you really don't need to worry much about it.
(Probably a little late to be worrying about it anyway, at least right now!)
Not sure what you're looking for in place of the quad rail - lots of guys like the Magpul MOE polymer option. It's lighter, at least. Some of it depends on whether you see yourself needing anything attached to it or not.
In terms of value, here are some brand new quad rail options on Amazon at about $40.
http://www.amazon.com/s/ref=nb_sb_ss...ad%2Caps%2C397
I'm sure you can find a Daniel Defense quad rail at three times this price or more, but not sure its going to either weigh less or work better for the cost. The point is that yours used isn't likely to be worth a lot more than one of these new, unless you find a guy who just aches to own a used Troy quad rail.
Unless the weight really effects your shooting, I'd just keep it on there. It looks okay to me, and you may find that you want to add a light one day (or some other attachment).
Shoot it often and enjoy it!