Personally I have been to demonstrations and watched with interest and also been to classes of various styles and watched with interest. I much prefer watching a class live than watching any demonstration. Thus demonstrations don't really mean much to me.
If someone asked me for advice who was interested in seeing Aikido in action I would advise them to go watch a class rather than a demonstration.
Strikes me that a person needs to KNOW about aikido in order to ask you about it. The idea of a demo at local events is to get it on the radar of folks who have never heard of it or considered it but might go "oh, COOL!" and come check it out.