Same as. Maybe we should both look at upgrading our sat navs before we look at cars!
I now do 20k a year, and in the end decided to buy nearly new on HP. Speccing out the same car (albeit 7 months old and 4.5k on the clock) on a 4 year lease term (vs my 4 year HP) is a fair bit cheaper in total but then if you look at what the (older version) model is worth now with similar mileage it's worth a more than the difference the total cost over the term.
Shorten the lease term to 2 years and it works out dearer to lease than to finance through HP and you hand the car back (if that bothers you).
So for high annual miles it's not necessarily good, but comes down to personal preference really.