RoM is not WoW, it is RoM, and its well worth a download, well worth playing, and well worth your time.
If you want accessibility, RoM has it.
If you want bright, happy graphics, RoM has them.
If you want to have your cake and eat it....well...
Most criticism of RoM comes from the item shop, and the fact that higher end gear needs upgrades that only come from there.
However,you dont have to spend a cent in RoM unless you want to. Theres advantages to be had from buying stuff in game, but the content and game itself are still there, still free.
Players who are familiar with 2nd Gen MMO's (EQ[1|2],WoW,etc) will feel right at home with an intuitive skill system, familiar feeling spells and combat, and a very familiar crafting interface. The game keeps some conceits from its asian heritage, such as click to move and a less than stellar targeting system, but for the most part has localised very well, and WASD is there if you want it.
Combat is as you have been conditioned to expect, as is gathering. In fact, most core mechanics are so familiar that you dont even notice them. The places where RoM differs are where it starts to shine. For Example,the game allows you to auto-run to a given map reference through a right click dropdown...handy for the sometimes long back and forths. The dual class system also distances it from its juggernaut sized competition.
Despite initial reservations, the dual class system is actually fairly freindly, and once you have levelled your primary to 10, you can choose one of two areas to go level your secondary, the area you just came from or a new zone with goat-like inhabitants.
Comparing an item-supported free to play game with a subscription supported behemoth is not really fair. Each game has been built and tuned to support itself financially. In the case of RoM, its an item shop. In the case of WoW its end-game grind to support recurring subs. For this reason, many players may have to retune their thinking slightly to not feel "ripped-off" by a free base product. Think of the cash shop as akin to buying a bundle of SMS messages, and it makes more sense.
When you get over the cash-shop disconnect, RoM becomes a real Diamond in the rough. RoM is to other Free to Play games as WoW is to MUD's, simply light years ahead.
If you played Perfect World, 9moons etc, youll love the ease and lack of Grind that RoM presents. If you need something that you can pick up and play for 20 or 30 minutes, RoM is it.
The game has bugs. The game has glitches. This games bugs and glitches are nothing compared to those found in subs based MMO's years after launch(Vanguard, AoC, WH:AOR anyone?).
So play it, you literally have nothing to lose.