For my opinion Nisus Pro is an excellent soft with excellent features and a good customer service (every time i write to nissus support they answer 8hours late and i'm still waiting answer for my ten mails to Mellel!!!!!!
BUT Nissus have ti improve some features to be the best, it's a shame you can't have a multi page (or a the less Two pages) view while writing on big documents!!!
As i use Nissus as a pro tool for my work , i don't care about 20 or 30 dollars more if the soft is good.
mellel i very good, i admit but their customer service is very bad and they need to integrate tools that Nisus pro do very ggod (antidote for french for ex, or grammatical checker….