So far I havent done a long enuff ride to honestly answer your question. (only had the bike for a little over 2 weeks)
My longest ride so far with the stock seat was about 200 miles and a very mixed type of roads. I really didnt feel cramped but did realise I would like to have a second set of pegs to use for extended freeway trips, for me this is to be able to move a bit more and strech as even in a car I have to switch possitions to keep from getting stiff.
With the long haul seat it seemed like I was pushed further forward just a bit but still not cramped.
Go take a test ride! Thats the only way you will know for sure!