Has anyone used tablexchange.com to secure hard to get restaurant reservations. If so, was it reliable? Is it appropriate or will I feel sneaky using somebody else's name?
Don't do it. You'd just be supporting a system that encourages people to make reservations they have no intentions of honoring just so they can sell them to others. This just makes it harder for honest people to make and get reservations.
It's a loosely moderated board in a free country, but please know that your question is offensive to many in this forum. Any "service" that distances a Chowhound from the Chow he seeks, or makes him pay extra for said Chow, is anathema to the principles of this site.
There is one poster on the Manhattan board who keeps recommending it, so it's obviously been reliable for her. I wouldn't use it for the reasons already stated. As to whether you'd feel sneaky, well, you're really the only one who can answer that.