I suppose I should lay out some of my thoughts on the game as well. In general, I like C&C. I'd gladly play it, and wouldn't mind running it a bit again. I used it to run a brief campaign for some non-gamers and have done some convention one-shots as well, enjoyable efforts which resulted in a lot of fiddling with the system and some house-rules. However, that hasn't stopped me from noting some pretty glaring faults in the game and its supplements.
The writing of the C&C PHB is at best inelegant, at worst obtuse. Its written in emulation of Gygax's flowery overwrought style in AD&D, which is endearing at first but wears thin fast. I'm fairly sure a competent editor could slash the page-count by a third, maybe even a half, without losing any real content. Unfortunately the one virtue of Gygax's textual excess, a sense for "actual play" value, is rather lacking. There's little useful guidance on what character's are actually supposed to do in a game; the unstated assumptions to give it context only there if you have an existing familiarity with D&D, and specifically pre-WotC D&D. Perhaps not an unreasonable expectation given C&C's target audience, but it makes the PHB useless for anyone outside that range.
Some parts of the system are tightly detailed (many of the class abilities) yet other parts are so loose as to be little better than authorized hand-waving. This creates a series of jarring speedbumps during play, as the game cruises through situations handled by on-the-spot rulings, but stops dead when something specifically-defined comes up. I wasn't familiar with D20 when I first picked up C&C, but having since read up on the SRD I can see how this disparity is caused by C&C's being a Frankenstein patchwork of overly-fiddly D20 feats and spells (copied verbatim from the SRD) layered over the significantly-less tactically-minded core C&C system.
The Siege Engine bugs me. The more I play with it, the more arbitrary it seems to just give a flat +6 bonus to rolls. There's no accounting for interaction with stat-derived bonuses, and there's nothing dynamic about the Primes. they're binary, simply there or not.
The World of Erde, the official C&C setting, is arguably the worst campaign presentation I have ever read. A rambling, Tolkien-derived faux-epic that spends most of its length laying out a millennia-long history offering no more useful input for adventure planning and running than the sketchy generic fantasy background already implied by any given set of D&D rules. Plot hooks, locations and NPC's are nearly absent, and the countries on the maps are barely described. The maps themselves are a disgrace, blobby, blurry uninformative and poorly conceived. But the worst part is the core (indeed only) conflict of the setting, a dark overlord who kept the world in eternal winter, has already been dispatched by an adventuring party that I strongly suspect were the PC's of the writer's own campaign; this ties the bow on the impression that Erde is an act of world-creation intended to be admired but never touched.
Maps in general are a weak point of TLG. Several published C&C adventures us seemly randomly generated dungeon lacking any discernible reasoning for there layout. Outdoor terrain regularly is set to exaggerated scales (Assault on Blacktooth Ridge puts the "nearby" adventure site approx. 80 miles away from the home-base village; So does The Slag Heap)
I mentioned the lack of an "actual play" sense to the C&C rules, and I think that's a criticism to be levied against Troll Lord Games in general. Their products, their designs, their marketing are all about aping the perceived feel of earlier editions of D&D and the glory days of TSR, something that often hurts the utility of their offerings when trappings and nostalgia is served before practicality as actual game materials. In a way, the sincerity of it is endearing; TLG is trying to revive a bit of the past they are obviously fond of. But as such attempts tend to do, the results end up more as unintentional parody than perfect recreation.
The core C&C fanbase is, bluntly, a bit hard-headed. Not just the miserable grognards who use the terms "3-tard" and "4-on" with a sincere lack of irony, but also many folks who laud non-critical praise on even the most typo-ridden TLG releases. About the time I got shouted down for discussing my disappointment in Erde, I realized that crowd wasn't for me.
But … despite all of the above, I keep my C&C books.