SSD's are worth the extra money for those willing to pay roughly a dollar per gig for high speed storage. They are extremely nice, but if you are on a budget with an Intel build check out Intel's SSD caching you can use a smaller 60GB hard drive and get almost the same results. See here - http://www.pugetsystems.com/labs/articles/How-it-Works-Intel-SSD-Caching-148
SSd's are used for Loading operating systems, games and anything else you want to load quickly. (some video editors who move rapid amounts of data, but in small amounts use SSDs. (youtubers) I hope this helps! Have a wonderful day and let me know if you have any other questions!