how good is the hypothesising at that Niw Englisc site?

Haven't had a chance to give it a good lookover, nor thought about all the ramifications of some of their choices. It acknowledges the Great Vowel Shift and retains the Englisc third person plural pronouns, eschewing the Danish ones that snuck in during the Danelaw. Whether the loss of grammatical gender is valid I don't know. I would suspect that it was also involved in the changes that went on as a result of the Danish influence. The choice of the as the invariant definite article is arbitrary and as good as any other, I suppose. Haven't studied the word choices in great depth. I'm a little bothered by their decision to retain the n in the indefinite article regardless of the start of the following word. Seems its assimilation would have occurred without any outside influences.

I guess, all in all, I'd give it mixed reviews.