I dont think its too flashy at all. I was thinking about getting this same bag as well but had the same concerns as you did. I saw one woman one here that showed the bag being worn and it looked gorgeous. However, I havent been able to see that many model pics of the bag being worn so Im unsure as well. I may be missing a post here with model pics of the galleria but someone should definitely start one so we can all see! hint, hint.
have you checked out this thread:
http://forum.purseblog.com/louis-vuitton/my-galliera-gm-finally-in-w-pics-349601.html
As someone else stated as well, the gold plate is primarily hidden by your arm. You do not see the gold plate for the most part. I do not think the bag is too flashy.