While I obviously wasn't there for the English leg of the extended Goo tour that Spin has in mind, Kim and I were at the Warfield in August, 1990. It was our first concert-going experience as a couple. We sat in the front row of the balcony, stage left. During the Nirvana set, in which the floor was filled with a surging pit that alarmed Kim -- who had missed out on the period when punk turned to moshing -- I had a hard time restraining my desire to hop around. To compensate, I slammed parts of my sitting body into the metal handrails to the front and side of me. I think I bruised myself.
It's worth noting that Kurt, who mostly stood stock still in the other two post-Nevermind concerts we attended, moved all over the place during the performance, at one point surrendering himself, guitar in hand, to the pit, which passed him around for quite a while as he hacked at the strings. If my memory can be trusted -- and it usually can -- he ended up many feet from the stage and then had to be passed back -- not hard, since he was super-light -- for the next song.