If you have done your research and know what you want and what price you are willing to pay, sure. If not, use the show to do more research and get a feel for prices. We figured out what we wanted doing research and talking to folks, including at the RV shows. We bought used and got just what we wanted. Our only disappointment is the fading of the front cap and it turns out our mfg along with a few others had a problem for a year or two. Factory declined to do anything on ours (still had some warranty left when we got it), others have had a nice paint job done..
Weights, floorplans, etc all play into decision. Please don't get sucked into "sure your truck will pull this" pitch by the salesman. Check it yourself, especially your available payload and hitch limitations.