Agree with most of what you say there - the Navara I had would cruise along very happily on the motorway with room to overtake (and was happy above the speed limit within reason - oh noes!)
But less space than an estate, in some ways it feels like that in terms of perception. Sure more litres of storage but in many circumstances less usable space. I changed from Navara to E61 and in the E61 I have more usuable space most of the time.
I had a hard top on the Navara for the last year I had it, previously open. When open you have plenty of piling space but no dry storage at all, with a hard top you have reasonable height and probably similar space to the E61 with back seats down, but it is not practical in the same way as an estate is. You have to clamber around in it, you can't access it from inside the car, there are not the compartments for stowing small things / protecting things etc.
As I am not a tradesmen, the estate offers more usable space for almost every application. Only the odd time like snowboarding road trips or dump runs does the estate space seem more limited. Also the cabin on the E61 as welll as being nicer and more comfortable is roomier, particularly in the back.