I think that due to the genuinely global nature of the server's population that 1.5x exp coupons to be used whenever might be more practical than a server-wide exp event (for whatever reason). Not sure how easy this is to implement, though.
I agree with Matt's post. 2x is way too much. 1.2-1.4x exp is always still worth training for; at the same time if it isn't used too much it won't break the game. After all, 1.25x would only add an extra 1m exp onto your bf leech.
If we were to get an exp event, it's to show what people in the server would think would be more suitable for the current server rates. Personally, an exp event here and there isn't a bad idea of course, it can be a bad idea if exp events are done too often with too high of a rate. As well, it could get people off their butts to go training. I oftenly had this problem at many level ranges, where there just weren't enough people training. If I could throw down two votes, I would vote for 1.5 and 1.25. Not as high as 2x, but not too low at the same time. 2x should be kept for server compensation from rollbacks, as always. 8x is way too fast.