I used to disagree with Semp when this topic came up a year ago when I was building my new comps. After a year of using an SSD in both gaming boxes we have, I tend to agree with his statement now. It really comes down to if you care about waiting 15 seconds, or 30 for Windows to boot. I've not seen a system that boots in 5 seconds yet, as just getting to and through the MD bios crap takes at least that long, before the SSD even gets to start booting Windows, so don't expect it to be even that quick. Most systems are still in double digits for boot times from what I've seen - maybe some MB's you can mess with the bios boot up stuff to turn it off, I'm not sure about that, as I've got an ROG and a Sabertooth board, 2 of the best and most expensive, and I've never been able to make them much faster in boot.
So, I went the Samsung route, the 830 128 gig as the 840s weren't out yet, and they have been very reliable, but Windows eats half that drive space, and you want to leave a little empty space for performance from what I've read, so you don't have much room for stuff other than your major games you play. Steam nowadays seams to be most of my gaming directory, and it's far too large for even a 500 gb SSD with 17 games I've got right now with Steam, so in reality, unless you drop massive $ on a very large SSD, many of your games are going to be on an old spinner drive anyway. I've not found a reliable way to split the Steam directory so that you can place just your favorite games on the SSD drive, and the rest on a spinner, it just doesn't work.
So, having the boot up time be about 50% faster is really what it comes down to, at least for me, or anyone using a lot of non Steam games. I had AH on my SSD until I read that due to all the small writes that can be a bad idea, so now it's pretty much only a boot drive, plus I have a couple of the DCS sims as they don't need to be in the Steam directory on the SSD drive. They do boot and access a fair bit faster, I wouldn't be upset if my entire drive system was as fast as the SSD drive, that's for sure, it's just the cost to performance ratio isn't really there yet for me. DCS A10 doesn't load that much more slowly on a Caviar Black 2gb drive than it does on my SSD - it is noticeable, but we're talking instants, not double digits in seconds or anything.
So, my opinion is yes, an SSD is worth it as a boot drive, but don't expect too much out of it, and again, if you're a Steam user and you have I'd say more than a dozen games, especially some of the new ones that are over 25gb like COD and Rome 2, don't expect to be putting your Steam directory on that SSD, unless you get a very, very large one, or a 2nd SSD that is again, large, for storage and games. You can get a 2gb drive for 100$ if you look around, a very good one, where as even a couple 500gb Samsung's will cost you close to 5x that, or 6x even.
