The best thing you can do is sit down and actually play with players. There are plenty of players at leagues who will be willing to sit down with you and teach you deck theory and matchups since all you're doing with a membership here is paying for just that, deck theory and matchups. If you happen to belong to a league where money trumps player interaction, then I suggest you find another league if that is possible.
As to if it's worth it. I guess that depends. I don't see the need to get on because I'm generally really good at the game and can build what I want and craft it through play testing. The main problem with the membership here is I don't find it challenging to me since the decks only cover what the writer considers meta. For example, I wrote a article here about Pidgeot-EX when it was revealed and some liked it, but others didn't because it wasn't another Yveltal-EX article, something I didn't find challenging. Since I'm the type of player who wants something more and the membership doesn't offer me that.
However, since these are meta decks and I prefer to play rogue, for better or for worst, I can see list that people consider standard and can craft my build according to those list. The main thing is I see most of this from the leagues I go to and I have a fairly competitive play group so I can get what I need from that. There are also a ton of YouTube videos outs there you can watch with a lot of competitive players. Off the top of my head you have the guys from Some1PC, Derium's Competitive Pokemon and Rare Candy, who I personally watch.
If you lack a real play group and belong to a league where the players tend to not let new people in a group, then I would say go for it. The other side I didn't look at is what that service means for the community. The memberships also act as a way to sponsor players. It lets those people share their knowledge (like paying for college) and lets them hold free, and yes I said free monthly tournaments where you can win actual product that get sent to you if you place high enough and I think that alone makes the membership worth it. I do feel it's a bit expensive but with all the perks you get, you may find it worth your time.