I like Twitter you often get people of similar interests getting together much like this. I find its good to praise and complain about things big and small. The advantage of twitter over say facebook is once I posted something on a supermarket's Facebook page. They didn't like it and deleted it. A company can't do that on twitter and if it gets retweeted, favourited with hashtags it can get a lot of (unwanted) attention.
The BA twitter team are amazing. They have helped me with pretravel queries, post travel feedback and a bit of banter as well. I think the response times are very appropriate too for the levels of queries. Admittedly some companies twitter feeds are better and more responsive.. others are pretty awful. I'd say it's a valuable resource.
With regards to the BA staff here.. my experience of them is that they were no use. I can see that they have done some great things for some people but the response times for me were not the best and they hadn't bothered to investigate or do anything.