Pros
Probably much better, if you were hired pre-2004 or 2014 staff reform under the concours/ as a permanent Eurocrat (so you get all the perks while others on precarious contracts do the work for you). The EU institutions keep going on about human rights, paying people the same for the same amount of work etc. ... but they are doing the EXACT OPPOSITE when it comes to (a) recognizing credentials of the millennial generation (often we have more degrees than the older folks, plus more international experience - which should be good for the EU given that it's supposedly international ...) and (b) paying us at the same level as permanent officials. So in reality, the EC has created a second class of workers that work more than the permanent officials - for less money, fewer benefits and less security. Here's your problem with the EU in a nutshell: Unless you have connections, you will not advance. It's like a modern day feudal system. If you can, stay away ... the EU dream has long died at the hands of corrupt EU officials - just look at where Barroso works now and you get the idea...
Cons
Advancement, hiring or recognition have nothing to do with merit or how hard you work - the only way an EU career works for you, is (a) if you are a political appointee or (b) if you have other networks that help you advance (spouse, parents). If you have an alternative position in your home country - take it! It's not worth working on a temporary contract for the EU, if you have to go back to your country of origin after a few years and have to start all over again (re: networking); plus, only a few industries outside of the EU apparatus care about EU experience (e.g. some international law firms and consultancies; maybe national government agencies). I'm surprised that temporary agents haven't yet started a class action lawsuit, given that they are doing the same work (often MORE work given lazy permanent eurocrats that just wait for retirement) for lower salary and benefits ... I've heard first hand that people can enter without a concours, e.g. as political appointees or spouses, while the rest of us have to go through a never-ending series of tests. Where's the justice in that system? It does not exist.