Cheap Yamahas? Action more like a square neck dobro. Not straight from the store generally, but within a year. I've seen several over the past few years which needed a neck reset (ie, absolutely no saddle height left to work with after the neck relief is set), and I've personally setup several by trussrod and saddle adjustment. These were mostly ply tops except one classical which was a lousy factory setup if I ever saw one. Now, I'm not in the business of guitar repair, I'm just a lowly instructor who provides the service to my clients only. Two of these instruments were returned to the retailer.
Having said this, of course I've seen some very worthy cheap Yamahas too, but the same odds don't apply to the Seagull family in my experience. Though I expect that humidity, or lack thereof, might be a contributing factor in these cases, I've seen enough to recommend other guitars.
Particular model numbers? I haven't committed these to memory, sorry, but I could find out easy enough. Now that I think about it, I'd bet these offending instruments were all bought at the same store within the last five years...Oh oh...
The much older Yamahas tend to be better. The ones which have lasted this long usually need a good setup but otherwise are quite good.
I agree about that giant sucking sound. I live in an area which gets alot(!) of tourist traffic in the summer and inexpensive merchandise just vaporizes. Touring musicians from the US and the UK have been known to pick up those Seagull/S&P/LaPatrie etc guitars.
Want to know where to find some of those used guitars which haven't "gone south"? Call some former guitar students. There must be millions of ignored guitars under teenager's beds. They sure weren't at the yardsales this year!