I doubt if you'll get many takers for a comparison between mnoGoSearch and phpDig. Installation and configuration can be a painful and/or time consuming process. Why put yourself through that again when you've already got a product that works great right here?
That said, I will make a few surface observations of mnoGoSearch. Their search engine seems to be comparable in functionality to phpDig, which is nice. The fact that it's free and open-source is nice, too. However, I am spoiled to a vBulletin style of message board. The mnoGoSearch message board makes it harder to read what's been posted, since you are forced to look at every post for a thread one at a time.
I think Charter is missing out on a few things though. Did you see what their pay support costs?
Talk about sticker shock! Maybe I should offer phpDig installation service with fees like that.
