Iain Dale's post and the comments thread left me somewhat bemused at the long discussion of why people are leaving the UK. It's worth noting for a start that net immigration is still positive, and that nearly half of those leaving the country are foreigners returning home.
But it got me thinking - a number of the commenters were commenting on leaving England for Ireland. There were a number of reasons I did the opposite move, partly due to the Darling Wife, but also due to the fact that there were more opportunities and better money in the field I work - I'm a CCIE in case you're curious which (supposedly) means I'm very good with those network things. Having been born in England to British parents, I'd always felt an affinity to England and had wanted to work over here for some time before finally making the move. Despite all that, when I did move over, I had moved with thoughts about moving back to Ireland after a few years. Those plans have been put on hold for the foreseeable future.
The reasons though run deeper - for all the complaints about the reliability and the punctuality of the train service from Ingatestone to London, it's no worse than commuting on the DART was in Dublin. Yes its more expensive, but I get paid a lot more over here, so I can live with that. Property prices in Dublin are as bad as most of London. The Republic's electoral system gives you essentially a choice between Fianna Fail and the "Not Fianna Fail" coalition - at least in Britain there are two main parties, even if it is getting harder to tell them apart. The overall tax burden isn't much different. The weather is a lot worse (there are actually vineyards near Chelmsford - there isn't enough sun or heat in Ireland to grow grapes).
Dublin itself is also getting over crowded - the city has been badly planned - there are major issues with layouts, and the M50 is apparently driven in first gear all the way from Bray to Dublin airport if you're travelling during the morning rush hour - presumably because some loon thought two lanes on the main motorway around Dublin was enough. The planning process for new roads is a nightmare - in that plans are made, approved, go through a public enquiry, and then just as the builders turn up to make the road, somebody discovers a medieval rubbish dump and insist the road be rerouted or delayed for two years while it's excavated. And all this under a system where the government spent a lot of money hiring a consultant from Madrid to tell them if they could avoid the three year planning process and worked 24 hours a day on building infrastructure as opposed to working 8 hour days they'd get stuff done within a year instead of taking five years.
In addition, the huge influx of Polish immigration is putting additional stress on, well, everything. Housing, transport, education - one calculation is that 5% of the Irish population is now Polish. 
Last year, my sister and I did our first driving tests within a couple of weeks of each other. We both failed. I failed several more attempts before finally passing earlier this year. My sister is still waiting for her second attempt.
And while we're on the subject of public services, the NHS, with all its faults, is a huge improvement on the Irish Health Service. I had to pay €40 for the privilege of visiting a doctor the last time I went to one before moving over - not paying my NHS doctor was a mighty relief and the removal of a source of stress.
There is an old saying, the grass is greener on the other side of the fence. It may look like the grass is greener on the other side of the Irish Sea - but in Dublin at least, it's definitely not much an improvement on London and the South East.
 This is the reason Fianna Fail have ended up in government after every election since 1987. It was only a falling out with their coalition partners and the fact the numbers just worked that led to the only two and a half years they've not been in power in the last 20 years.
 It should be pointed out I don't think that Polish immigration is a bad thing - I just think that Dublin wasn't coping very well when I left three years ago, and I can't imagine a huge increase in the population since I left is doing the place any favours in terms of infrastructure.