The Tacoma-builts are obviously newer (2005-2008), so it's probably easier to find one in excellent condition. Westerlys are anywhere from 1967-2001. Coronas slipped in there from 2002-2004. I hear you about the F50R. I recently scored one out of the New Hartford plant (2009-2014), and it's just the ultimate 6-string as far as I'm concerned.
I had the same question when I first arrived - Is the Guild quality and tone any better from one plant as opposed to another? The answer is basically no. Guild has been remarkably steady in producing quality guitars throughout its various plant locations.
Looks like
a nice burst Tacoma-built F50 is up on ebay for the next few weeks, with the unbraced, arched maple back instead of the braced rosewood. The guy's asking $1699, but he's accepting offers. In any case, good luck in your search!