IAMORGAN, I look forward to hearing how it goes!
Whilst I understand why some may feel reluctant to eat outside of the lounge (or the food available on board) because it's been paid for already, it boils down for me to "you get what you pay for". (For the same reason, a lot of people take out private medical insurance even though the NHS is available.)
If I have a few hours at the airport and don't need to work etc, why endure what could at best be called the average "free" food offerings in a lounge (or on board) if there's a better alternative available ? IMO, for a premium leisure traveller (paying for CE, CW or F) or a business traveller (on expenses), twenty quid for a steak or similar isn't much in the grand scheme of things.