A SSD is definitely worth it if you can afford it. Drawbacks do exist to it, but the speed, durability, and reliability made it very, very worth it for me.
I wouldn't personally purchase a Vertex2, but there are a lot of people here who have them and have used them with great success. The Vertex is one of the fastest data storage system on the market today, and you could make a pretty solid argument that is the fastest, as it always tops the speed charts. With that said, any reputable SSD is going to be plenty fast and if you were to compare the Vertex 2 to the Crucial C300, you probably would notice little difference between the two despite the Vertex having the statistical edge on paper.
How much info is on your HDD now? I went to 120GB SSD and that will hold me till the cows come home. If you don't use tremendous amounts of data, saving a bit longer and getting a larger size SSD is not a bad idea. The more frequent complaint you will see for SSDs are related to the users wishing they went for more physical size. Also, Intel is going to drop the price on SSDs while increasing the capacity.