I live in Somerset, not far from Yeovilton and helicopters. My "local" airports are about an hour away. Extending the runway at Bristol is, I believe impossible, same at Southampton/Eastleigh, not sure about Exeter but I doubt the traffic base is there. As a child I lived in Chiswick right under the 28R (as it then was) approach Viscounts, 707s, Tridents, VC10s - you don't know noise until you experience them. Most of my working life was spent in Maidenhead which suffered but not as badly.
That means if I want to fly long haul I have to go somewhere in Europe and then pick up my long haul. I like flying (!) but I also recognise that take-off and landing are probably the riskiest bits. So, to avoid the hassle I take the train up to Reading and then RailAir to Heathrow or another train to Gatwick. Depending on flight times I might spend a night at an airport hotel.
Personally, I'm happy to see Heathrow given the opportunity to expand. Quite apart from personal preference I think it's the right solution for UK PLC. However, I also believe it should be part of a much wider plan relating to airspace planning and airport planning for the UK as whole. That in turn should be part of a wider infrastructure plan so that when an airport expands it gets rail links as well as road.
Oh, one last thing. The airlines should be told that their use of an airport is dependent on some kind of accommodation with the railways and bang a few heads together at ATOC (or ROG as it is now known). Coming home from San Francisco last week I couldn't book "advance" tickets because I couldn't reliably predict which train I would be able to catch. In fact we landed on time (after a 40 minute delay to departure) at 1330 and caught the 1530 from Reading but because I couldn't predict which train I'd catch we had to buy expensive rather that (slightly) cheaper tickets.