My experience with Salvia is similar to most of the posters here. It is a very strong hallucinatory high, very much like a dream. I'd say the closest thing I've had to Salvia is PCP. However, pcp gives the same type of trip as salvia but lasts for hours as opposed to minutes.
I went into my local smoke shop to grab a pipe. The guy who owned the place was selling some salvia to another customer. After the customer left I asked him about it. He says "Oh yeah man, this stuff is the real deal, just don't do it when your driving." At the time I thought, "yeah bullshit, I doubt any legal herb is gonna be THAT strong." So I bought a gram of the 50x stuff just to give it a try. First time I smoked it I made the mistake of packing a small amount on top of some weed. It did jack shit basically. You have to take at least 2 large hits of full on salvia smoke to really get the full effect. So thinking I had been bunked, and at that point it is what I kind of expected from it, I decided I would do a big bowl pack of it and if I didn't feel anything I would toss the rest out. After I exhaled the second hit I was out of it. 10 minutes later I had come to and only had faint memories of what had happened during the trip. The most memorable part was that on the television there was a show where they were interviewing Donald Trump, and he was speaking directly to the camera. When I was tripping it seemed like he was speaking directly to me, I might have even been talking back, I dunno lol I was fucked up.
Anyway, salvia is a good time if you can handle that type of high. Unfortunately in my circle of friends I am like the only one that really enjoys that kind of out of body experience high. So I never have anyone to do it with. If you want to see some funny shit check out the videos on youtube of people smoking salvia. Some of them are friggin hilarious, especially if you have gotten really lit off it, because you can relate to the people in the videos and the shit they are doing/saying.