Folks, sometimes I've been quick to categorize "good and bad periods" for instrument companies. It's something that obsessive instrument "nurds" like myself tend to do ad nauseum. I think generally the information is accurate, cause it's based not only on personally playing thousands of different instruments, and hanging out a lot at the stores, whether at home or on the road, but also anecdotal stuff from other players and tons of articles. BUT..BUT it doesn't take into consideration that all of these companies made some superb instruments even during their "bad" periods. Some of Gibson's J-45s from the sixties have mellowed beautifully and because of their over-bracing, have weathered the years well. Likewise some Martins from the seventies. The real barometer is the prices charged by knowledgable dealers. They know what the traffic will bear and price accordingly. I've scored some wonderful instruments that were priced low because of a bad "vintage". For what it's worth, most Martins made in the last 4 years strike me as virtually similar to the Collings and Santa Cruz instruments that almost took the high end market away from them. (Taylor also scared the pants off CF the third as well). Even Gibson are back in the market seriously with their bluegrass five stringers now, and for them it's been a long long time!
Rick