unlimited

I quite like O2... I've been with them almost 9 years now and never really had a complaint... until now... As part of my contract, I got offered an "Unlimited Web Bolt on"; great I though - I could use my XDA for most of my work when moving around! Then I read the small print... subject to...

Is apparently unlimited...can anyone confirm this, or have any experience of O2’s unlimited tariffs ? We only need 2 Iphone’s, and could put them on either personal or small business – but BOTH seem not to allow commercial usage of the unlimited data (and only 18.24, or 36 month contracts)...