On your recorder were you running line in or mic in? If you were running mic in then there could be some reason for the problems. After listening to your recording, yes there is a little distortion, that could have been in the PA, your mic config, or some other factor. However it sound very good none the less and its a very listenable tape. If I were you i'd be more mad about the clapper next to you! Try it again at another concert and see what happens, the distortion is not that bad in my opinion, and it just sounds muffled which could be for many reasons.
Just a word of advice, there is no catch all. My stealth rig cost me about $3,000 and I still get distortion at times, or a bad recording. there is no perfect rig that you'll find which makes a perfect tape all the time, Mr. Church can't make one, DPA can't, Schoeps can't. However what you bought from Chris will help you get much better recordings.