I bought a White 6342 last year, which as others mentioned is a 12r30", 13r15" planter that flexes in the middle.  I did some work to it, but nothing related to the frame and I don't see where there would be any issues with it that you couldn't have with any folding planter.  The front units are a little bit of a pain to fill when the unit is folded for beans, and the access isn't great for working on them either, but it's better than having all of the row units on the same frame for 15" rows (which is what I changed from).  My planter has the optional wing lift wheels, which is an extra wheel on the outer section of each wing that you use when it's folded out for 12 rows.  I think that you would have a lot more wear in your toolbar if you didn't have these wheels to support the outer section when you raise up at each end.  When you're planting 15" rows, you just turn a valve to hold these wheels in the up position all of the time.  The only bad thing is that they pretty much fill up the space between two row units (like most planter wheels) and so there's that much more to work around.  Overall, I like the planter and love the White units compared to the finger pickup planters that I ran in the past.

Mike

Edit:  If you want to see how these planters fold and unfold, they show a diagram on the White website if you look through the planter literature for the 8200/8300 series (at least they did last year).