Always found the stewards to be absolutely fine.
Once had one come and talk to me about the flag we had draped over the front of the 1st tier. It wasn't causing a problem but he'd had a report it was. Turned out it was somone else's flag further along that was draped over too much and obscuring view below. But the steward talking to em was great, polite, explaining what was wrong etc. Have to say I was polite back and it was all dealt with amicably.
Sometimes I think it's how people react. If a steward has to speak to someone and that person starts getting absuive then the steward is going to find it hard to continue being ultra polite.
Another time I took my camera to a UEFA Cup game and got tickets near the tunnel. Steward came over and told me I couldn't use it. I thought he was joking (because I'd never had a problem before) and carried on. He then got the Senior Steward (the guy you see stood in the players tunnel during games) to come over. The Senior Steward explained to me it was a UEFA rule and they had to stop people. Again he was very polite and understanding and having explained the situation I accpeted what it.