This is a big "it depends" question. Depending on what your goals are, it can be "okay" or it'll be a total waste. If you are looking for interesting ring games, it's total trash, as the ring games are play money only and there are no prizes to be had there. If you are looking for small stakes tournaments, it's not awful, as it seems pretty easy to at least make your subscription fee up if you aren't a complete idiot. I hit for $15 last night and I've only been on the site for 10 days and haven't played poker at all in the 3 years prior. Keep in mind though that that $15 was for taking 9th in a tournament with about 1780 runners and playing for about 3.25 hours, so in comparison to something like a $2 buy-in tournament on a regular site, its a terrible payout.
That said, they do offer a few tournaments with some big first place finishes, like a 7 day cruise, the $5k live WPT buy-in, and boot camp prizes but those are winner take alls, so it's pretty limited. They also have a monthly $10k prize pool tourney which offers the best deep payout structure, paying at least $20 to the top 250, and $1k to first.
They do gate the better tournaments to a certain extent as well, as they use a point system, called Tournament Points(TPs) as the buy-in currency. All subscribed accounts get 500 TPs and are reloaded once a day at midnight ET if they fall below 500. The big tournaments require 1k-2k TP buy-ins however, so you'll have to either win a satellite or build a bankroll of TPs by finishing "In the points" in MTTs/SnGs to get access to those.
The signup process is simple and since it's a service based site, you can use pretty much any old piece of plastic in your wallet and have no hassles(see next paragraph). The download process is kind of annoying since they use a wonky java applet to "launch" the download. I find this rather stupid and it seems to cause other people issues as well(a google search confirms this) since most Internet Browsers will block it by default. Once you get past that though, the install is simple. The client itself is okay, but you can only play up to 4 tables at a time, which will bother some players, I'm sure. Overall, the client seems fine for the intended audience.
One note on cancellations, I had previously used this site back in 2009 and it was a pain in the ass to cancel since you have to call and talk to a billing rep. It seemed basically impossible to actually get a hold of anyone at the time(always got an automated service). I ended up canceling the card that I had used during signup to stop payments to them. I don't know if it is still this bad to get a hold of a billing rep, but you still have to call to cancel, so I would suggest using a prepaid card if you decide to signup and cancel later.
As far as actually getting your winnings from them, I have no idea how this is. They do require submitting ID for address verification before they'll do a payout. In theory, once you're verified, they should be able to send you checks on demand since they don't have to go through any 3rd party laundry systems, but again I have no actual experience here and their overall customer service doesn't instill confidence.
They do have a couple VIP perks as well, but they are seemingly rather lack luster. You get online access to Bluff and WPT magazine, and coupon codes for services(entertainment/dinning/etc...) I have no idea if those are any good, I haven't looked into at all yet. You can also get a discounted rate(~15%) on the WPT bootcamp prices if you're inclined to go to one on your own dime.
Given the numbers that I have seen so far, it looks like they are only paying out around half of the subscription fees back to the players each month in prizes, so they are getting a pretty healthy margin on the whole thing. Given how soft the games appear to be, a decent player can still make some money here, at least in straight dollar terms. If you include the amount of time needed to make those dollars, most players will find it a waste though unless they are getting something else from it, like experience(which is debatable)
Overall, I would say the site is best for new players looking to the learn the game(tournaments in particular), and casual US players that want to play online and feel like "something" is on the line, as there is "some" competitiveness(again applies to tournaments specifically). Some experienced players might also want to try and take a crack at winning the Cruise/$5k WPT live event prizes. Of course, even if you win, you still have to actually pry the prize from them.