The big question: GW or GW:F?

After playing the Factions Event (and never playing GW before) I'm not sure I l will 100% like GW, but I think I now like it enough to bet $50 on it. I can't say I was increadably impressed with the Faction Event , but my problems were more with the limitations of the event, and not the game. There was not any tutorial in the RP side. I'm coming from WoW, and at first I was disapointed in the combat system...but looking back I reallize that its just a different thing to get used to. I really wanted more from the event to try out...so some ways it was limiting. Now... here is the big question:

Should I just get GW:F, or should I buy GW first? Another way of asking this question: What do I get from GW that I can't get from Factions, besides more PvE time (and the ability to play GW between now and April 28th)?

Based on your post, I'd say get the original first. GW has a sizeable tutorial area, I've heard of people quitting the game before they even left it thinking that it was the extent of Guild Wars.

Access to the Prophecies campaign, which is probably bigger than Factions. Access to Tyria, the setting for the Prophecies campaign. Access to the Prophecies group of skills, which are unavailable if you only buy Factions. Basically it should double the available content. Also, you've already mentioned the point that you'll be able to play it until the end of April.

Edit: Its cheaper too.