Bob,
Does inflation not erode all returns. I would have thought it does and therefore one may as well have the 'before tax' pension investment working for you over the next 25 years rather than a smaller after tax personal investment.
I agree with you Beaky. Its crazy to put off starting a pension until you are 35 or 40 if you are in a position to start you one in your 20's. No-one is saying he should all of the 600 a month into a pension. Assuming he pays tax at the higher level, a pension contribution of €200 p.m. would cost him a pricely sum of around €118 and that doesn't include relief on PRSI etc. Still leaves him €480 odd to do what he likes.