Great post above from CC. Some very useful information and insight. Not very relevant to me regarding the products available, being a Brit. However, the general sentiment is very sound.
I am not yet in need of a retirement visa/extension but will be in the not too distant future. I have been taking advantage of the current exchange rate and have transferred circa 1m THB at rates varying between 45-46.9 to the GBP solely for the purpose of the 'retirement account'. This compares to rates of 40-42 to the GBP in the not too distant past. This, combined with a very buoyant FTSE at the moment has put me in a fairly strong financial position.
Make hay whilst the sun shines - it won't stay like this forever.