I'm surprised by how similar your convention perception is with mine, as the last time I attended a science fiction convention was in the early 1990s. The conventions I went to were always a mix of all the scifi out by that time. I've never been to a Star Trek only convention. I always had a grand time with other convention goers. We were all there for a shared love of science fiction. It was like being with a huge group of friends, where you could start a conversation with anyone. The cosplay was varied and wonderful. It was a chance to shop with non-local vendors. Some selling unusual, hard to find pre-Internet, scifi themed mass produced items, and some artists selling their own creations.

I did have chances to meet some Star Trek stars. In 1970-something -- before TMP was released, I met George Takei when I was heading towards a hall for a panel, and noticed someone sitting at table in the large hallway outside. It was Mr. Takei! I was so shocked, I babbled. He was so nice and charming, and he didn't call security on me, lol. I met Nichelle Nichols at another convention. The line to meet her was crazy long. The event coordinators said that she was leaving at a set time, no matter how many were still waiting to meet her. Ms. Nichols said that she wasn't leaving until everyone who was waiting in line met her. That fans helped her get to where she was, and she was going to meet those fans. Kind to everyone, and took photos. Absolutely a class act. I had a chance to briefly meet DeForest Kelley not long before he passed. He was obviously ill, but still was there for the Star Trek fans, talking and telling anecdotes about TOS. A wonderful person who is still missed.

I saw Sir Patrick Stewart, Mirina Sirtis, and Micheal Dorn at a convention not long after TNG was first out. I actually met Micheal Dorn by being in line for an autograph. I didn't want an autograph, I just wanted to meet Micheal Dorn. Based on the crowd's reaction and comments when Mr. Dorn spoke early that day, I wasn't the only one who was surprised by just how good looking that man is under the Worf makeup. Sir Patrick and Mr. Dorn seemed shocked by the size and enthusiasm level of the crowd. Ms. Sirtis was just amazing and loving it. Funny, charming, and delightfully loquacious.

When "pay for a picture or autograph" became the norm was when I stopped going to conventions. I'm not big on autographs, and I wasn't interested in paying for photos. The fans at the convention were still great to be with. I do miss that part of attending conventions, the being with other fans.