I think the word implies a little more than just something that is a whopper - as obviously in this case size isn't the overiding feature.
I'd suggest that 'impressive' in all senses is perhaps a better description........... it's rare, it's beautiful, it's valuable, has a first class pedigree/designer, and to boot it's a real antique.
You get the drift Carolyn...........something that comes up suddently and is very impressive - a real whopper
