Do you still play? And what does premium add? It's sounds interesting, I might try it this week.
Nah, I stopped playing once my premium ran out and I had no money to spare. Once you get to experience premium it's very unlikely you will be content when you go back to F2P if you cannot afford to keep it going.
Being premium raises your level cap to 99.99 instead of 20, and, from what I can tell, a few of the more fun features of the game are restricted to Premium-only servers, though you have the option of traveling to a different server from the one you start with (for clan wars, exploration, etc).
Though a word of advice, if you plan on simply being a casual player, it is quite unlikely a premium will be worth the 20 dollars it is. A lot of the things in the game can be considered grinding, though it makes up for it by the fact that the ENTIRE MAP is terraformable and also the fact that premium allows you to have a piece of land, which reduces rate of decay on walls and such by 90% or so and oil based lanterns NEVER run out.
As a newbie, it would be advisable to join a village ASAP, which you can do once you finish the tutorial and choose a world by typing in the kingdom chat (if no one happens to be talking, the tab won't show up. just type /s and press enter and the tab will appear).
There is a steep learning curve. Very unlike WoW, RoM, Eve, Guild Wars, etc.