I went to see the Police (her in doors idea honest) in September. Our tickets were quite a long way back in the corner and to be honest we could see virtually nothing ( I know most will think I was lucky) But being an old bloke and having paid lots of money I decided to have a friendly word with one of the officials. Without hesitation he introduced me to another official who was holding a pile of 'on the night exchanges.' This resulted in us being moved to within a few metres of the stage and we noticed the tickets were £30.00 each more expensive face value at no cost to us. They are obviously used to people being disappointed with the not so good seats and have an efficient mechanism to deal with it as the block that we arrived at was empty when we got there and eventually filled up as more people caught on to the idea of complaining. So advice number one, if you don't like the seat for any reason, complain, they will relocate you.
Having said all of that, the acoustics were appalling. Now, like them or loath them, technically the Police are pretty accomplished. They sounded worse than a pub band playing in an empty swimming pool. It might be that there set up was poor, but based on my single experience of watching that show at Twicker’s, I have vowed never to return.
Sorry to be so negative, but it was advice you were seeking.
By the way is anyone else going to see Led Zep in a couple of weeks?