Aside from at least 50 2600 import carts that I have in my collection that I don't think are in the guide (in most instances, who cares?, but if you're going for completeness), I have a few bones to pick. Mind you I love the guide and all the new ground, but a few sections are a bit messy.
Now, is rarity for each section relative? Not that Adventurevision Defender should be a '1' because it was the pack-in, but it's silly to rate everything in a section between 5 and 8 because the carts are relatively uncommon (VIC is the best example.)
This being said, the Creativision rarity section is pretty limited. The games aren't that rare in the countries they were sold (with exceptions), and I think we majorly need to fix that section.
O2 rarities could observe more of a spread- rather than everything basically being 1-3, the more relative rarity a bigger section like this observes, the better. I would consider Killer Bees a 5 and count down from there. Turtles as 4's, maybe PT, Sid,NED,Matchmaker, Computer Intro, Keyboard Cr as 3's/3+'s, and most of the rest counting down. No doubt Quest, even complete, should be a 3+, whereas Conquest a 4, and Wall Street a 5... Quest was a pack-in late in the life cycle of the system. The Imagic games are 5/5+ as labeled and Power Lords is a nice 8.
Sure, VIC carts are uncommon, but the rarities for the harder carts are stretched more than they should be. I think most of the unusual carts should run from 4-6, and only the really unusual stuff hits 7 and 8. But at least half the library should run 2-4...
AQuarius needs a better spread, methinks- all 4's and 5's? We can figure for a few 3's in that library, I'm sure.
Channel F I would probably downgrade rarity as well- cart #1 is rather common, and a 3 at best. Baseball is probably second most common, and a 3 at best. Sure, ChF carts are an unusual find, but there are a few that just pop up alot more than others, and our rarities should reflect that. Really, Joe, I should write the intro to the section for the next edition (provided I have unpacked my collection by then). I actually had the system as a kid and played it alot- though I didn't have a complete collection at the time. I might actually have a complimentary word to say about one or two of the games.
If anything, the Arcadia games by Emerson are underrated, especially considering the rarities for other sections. I actually agree with the rarities better for this section, but if you're going to make Aquarius carts all 4's and 5's, you have to start this section higher- most of the carts are not '2' when you consider how many 2600 '2's you can find on a given month. Most people I know hardly ever see Arcadia stuff in the wild. I think it's pretty underrated in rarity, not that we should upgrade the numbers in the guide- but perhaps use this type of system to generate perspective. Are all the rarities going to be relative to the system or based on some grand overall scheme that applies to every system? When it comes to the Arc imports, they are much more common- Leisurevision stuff pops up all the time for many of the Canadians I know who have any luck finding stuff.
I'm really enjoying the guide, and I hope to help refine future iterations- even if just by being a thorn in the other staff's side.
I also support a DP guide to more recent stuff (As you've had it listed on the site) and something dedicated to imports and Jap releases (that's tough!)