I think that a real-life demo is much more effective to knowing whether or not the product works. If you're concerned with privacy- you can even have a quick test run to see if close family members or friends like it.

It would be bad if there were bugs or small annoyances like bad UI when the Angels or VCs are testing it.

If it's a prototype to simply show the idea and not anything close to a full blown site- then go ahead and give it a try. Advice is always going to be advice- it may or may not help, so believe in your product and decide what you might want to do.