I like it alot. I use the tactics trainer occasionally. The game explorer is the real gem. Because you have access to games played by Masters going back many years. Its a much larger database than chessmaster. Dont get me wrong invest in books as well, but the visual nature of this site will help for more than trying to read a book. The investment here is next to nothing in terms of price. Go ahead and get the gold membership for ! year. Added bonus is that you can participate in up to 10 tourneys at once, and you can even create your own tourney. Plus you have vacation time that kicks in automatically, if you cant quite make it to your computer to make a move before time runs out.
Membership

I'd suggest getting the diamond membership for a month so you can get a taste of everything. I'm a student as well and I don't regret it. I haven't devoted as much time to chess mentor yet as I would like to (and I plan on trying to do 30 minutes a day starting very soon) but from what I've seen of it I like it a lot. I think a regular schedule of tactics trainer, chess mentor, and the other tools on this site will definitely lead to improvement.
I've tried the demo mode of Chess Mentor and it looks good. It doesn't just say the move was wrong. It tells you why each of your moves sucks so there's a lot better chance of learning how to find the right move.
I'm considering to buy a chess.com membership but I'm wondering if the upgrade's like chess tactics/ computer workout/ and chess mentor, really improve my knowledge and understanding of the game. Some questions are, are books just as good? Is it much better than programs like chessmaster(wich I have a copy of)?
And a review would be nice too.
I'm rated around 1700 and I am a student who does not have a lot of money, so from someone who's like me and bought a membership, was it a good decision?
By the way, I could buy for a month, but I don't have a credit card, so then I would have to do all the work with pay pal, wich I don't know anything about, and if I do all this I would like to buy an annual right away.
sebas