I just wanted to thank everyone for their input on this - there was a lot of good information that really made me consider the options for which device to get.
I finally decided on the Sony 700 (which was not on my initial list) for a number of reasons - the biggest of which was probably the fact that I was able to actually see it and play with it in the store before buying. Perhaps a little strange in this age of internet sales - but that made it a lot easier for me to be comfortable with the investment.

again for all the advice.