Moneybookers and Western Union are fantastic, PayPal is very popular because of the simplicity, but it is also the number one scam method.
PayPal has a feature to file a claim and get all the money you sent right back to you with no loss (except to the person they're taking it from).
Moneybookers and WU fortunatly (or not) don't. They are equal speed, just less popular and a little more misunderstanding if something happens to your money.
I suggest, if you're doing trades, to just say you're using Moneybookers or WU and just go along for the ride until some one shows up. If you are too impatient to wait, then you deserve to be scammed.
PayPal < Western Union < Moneybookers = my opinion
/edit: if you want to withdraw the money as soon as it's sent, do WU, because to get the money in the first place you have to go to the WU location. Moneybookers and PayPal can put it in your bank but not your hand.
Hope that helped.