The answer to your question is it depends. There are a lot of factors to consider. The most important question is what do you want a ssd to do. Different configurations and different applications produce different results. A ssd may perform very well with one application and perform poorly with another application.
The absolutely fastest solid state drives are not designed for gamers and enthusiasts. The fastest solid state drives are designed for big businesses that handle very very large data bases. The last time I checked prices for those ssd's started at $9,000.00.
The fastest ssd's for gamers and enthusiasts are probably PCI-e based solid state drives which are multiple ssd drives configured in a Raid 0 array on a single PCI-e x4 card like those offered by OCZ.
If you are a gamer, then there a few things you should know. If the game is on the ssd, then it will load a lot faster than a game on a hard disk. If while playing the game you need to look at a map, chart, or list, then they will probably load faster. The ssd will not improve FPS. If you are playing a game online or doing something else online, the ssd will not improve anything. You are totally at the mercy of the world wide web connections.