I don't think the graphs look cheap on their own, but they do have a "look", which if overused could begin to look cheap - like the standard blogspot templates

I don't think the graphs look cheap on their own, but they do have a "look", which if overused could begin to look cheap - like the standard blogspot templates or an excel graph as examles. I don't think that is the case yet, nor may it ever be (you have to be a programmer to use these). Here is another positive: the graphs are fast. Really Really fast. You get the multiple-hosts pipelining trick for free. You get the fact that Google hosts these graph servers local to wherever your customer is. Google buys better network connections than you can likely afford. Also, some engineer(s) at Google's job is to make sure that the rendering itself (server-side) is wicked fast which is more than you can say about your company or graph library you are using. Speed is valuable and looks very professional.