Well Nokia does not sells the N810 stating it's a "GPS device". It sells it as a companion for your laptop that ALSO does GPS.
They don't sell it as TomTom or Garmin or Magellan do.
So there is no point in complaining about that.

If I would have looked for a good GPS than I would have looked for specific GPS products.
I do use GPS maybe twice a year and sometimes just for fun.. why would I need an expensive GPS chip ?

By the way, my 29€ bluetooth GPS receiver took almost half of an hour to get its very first fix (while my N810 took less than 5 mins!).
True, my 29€ bt GPS receiver takes few seconds to get a fix if I turn it off and on (within few hours from turning it off), while the N810 still takes its 5 mins EVERY time I try to get a fix.
But, for me, it far more than acceptable.

Note: "for me"