Absolutely. I have not pirated a single game since I got steam. Before that it was almost exclusively pirated games. no shops close by, and buying on mail order took FOREVER! and was very much hit or miss… And impossible to return.
I did buy most of the games that i enjoyed, and played a lot. Since i wanted the box on the shelf. but i still played the pirated version. since that was much easier then puling out the book and look at the 5th word on the 3rd paragraph on page 121 for the copy protection. :)