First of all, I must say I'm somewhat biased due to the fact I am a fan of Deadlands and that tends to colour my opinion a lot (such as being able to tolerate what I consider to be a clumsy rules system that is extremely munchkin-encouraging, terrible over-statting of NPCs/monsters, etc).
Lost Colony was a sourcebook rather than a stand-alone like Weird West and Hell on Earth Was. It was very similar to Quick and the Dead and Wasted West. However, it left a lot of unanswered questions in what I consider to be "basic setting info" and so I was expecting to find them in Lost Colony Companion (LCC).
Where, LCC is not a source book. It is a campaign book. If you have got the recent Great White Games (formerly PEG) campaign books for Savage Worlds (e.g. Evernight) then this is more that it is like. It does provide some insight and background but only with respect to what is involved in the Grand Campaign. It completely fails to answer what I consider to be critical info for the setting, like how many moons does Banshee actually have? (2 according to the novel Banshee Screams but 1 according to some random page in LC). Just how are the Anouks organised in their tribes? Are they like indians? Do they have live young or do they lay eggs? You know, stuff you normally get as a 5 page summary in most RPGs.
That aside, there is a lot of good stuff here. It's an interesting read in the old DL style of writing. There's a few things I don't agree with but it's a matter of style. It could use a couple of reference sheets or organisation sheets to help Marshals keep track of what's going on but it only takes about 15 minutes to make one yourself, which I have done for my current game using this product (only using EABA for rules instead).
So in essence, this is a good product but you must be aware of what you are getting. It is a Marshal's Campaign sourcebook, not a Lost Colony Companion!