I have been testing for about 6 weeks with our webstore.  Not quite ready to make the change from our old Miva Merchant store.  Initially the netsuite store seemed really slow, taking 10-14 seconds to load apon first visit.  After the site is contacted and loaded, all navigation seems normal.  After 2 weeks the problem seems to have gone away.  (4-6 seconds now).

But today, I decided to point my domain to the netsuite store.  Seemed to work fine, still 4-6 seconds, but after setting up descriptive urls for the store, I'm back to taking 15+ seconds to load the store upon initial visit, then navigation is faster but still slow, 6-8 seconds per page.