This is a tough one.
I want to like Mongoose stuff. I really do. But they make it tough to appreciate their products. Admittedly, I'm a stickler for editing--the way I see it, if you're going to drop $50 on a hardcover book from any other publishing industry (novels, for ex.) you expect that book to be edited properly. I don't think it's unreasonable to expect the same from game publishers. (Even if they're Brits. No, wait; especially if they're Brits....I'm speaking the red-headed stepchild of the language they created. Developed. Whatever.)
The Quint books have so-so editing, rules, etc--and that's fine. They're relatively inexpensive, so I don't have huge expectations. When the Bab5 source book preview PDF first came out, several of us pointed out that there were editing mistakes in it. Editing mistakes in the preview. Are you telling me that they didn't have time to correct those mistakes? That doesn't bode well for the rest of the book, but I'm a consumer....so I consumed....and found that the Bab5 book was riddled with silly mistakes. Even the back cover has an editing gaffe.
Ok, so that was disappointing, but we all drop the ball at some point in time or another. Eventually the Conan (1st Edition) book came out. Ouch. OK, ball-drop #2. Editing mistakes had been pointed out in other products (Steampunk, Cyberpunk, Sheoloth, more splatbooks, etc). Not looking good.
So a few weeks ago, after reading an empassioned post here on EN World by MongooseMatt, I decided that giving them a second go would be OK. I bought a majority of the Conan suppliments based solely on Matt (and other's) insistance that the products were better. (I bought them on line, so they hadn't shipped to me before this -->) Within a few days I saw posts about the Shadizar map and errata was released for Jeremiah....
So what are we supposed to think? Mongoose has some exceptionally interesting books, but some phenominally bad editing & grammatical issues. For those of us who cringe about obvious, repeated editing mistakes, Mongoose is not the publisher for you. The rest of you--let the buyer beware...