Goodyear also specifies a 8"-9.5" rim width for the 305/70-17 MTR, so the 7" TRD Pro is out of spec. not that you can't do it, obviously, just that the manufacturer does, in fact, specify a wider rim for mounting that tire.
those MTRs are nice tires. i had the old style on my '93 and loved them.
loud, but loved them. interesting to hear that you find the new MTR quieter than the Duratracs. how many miles were on the Duratracs you replaced? mine had ~42k when i replaced them last fall and they were insanely loud. like, full-on
mud terrain loud. not necessarily indicative of what would be normal to expect, though, as i really should've rotated them more aggressively.
personally, i was all gung-ho about the TRD Pro wheels this time last year. i'm generally not super into rims, but was drooling over them since they were first revealed at SEMA on the supercharged FJ-S concept vehicle. then the 7" spec was published and i quickly soured on them. in the end, i put my 285/70 Mickey Thompson MTZs on a new set of FN Five Stars, which i really, really like: simple design; proper width and backspacing; saved a lot of unsprung weight; and are very easy to clean—and keep clean—as well.
when the stock Trail wheel is 7.5" width, designing a 7" wheel for the "Pro" seems like a real boner move by TRD to me.

only seems smart to me that [MENTION=85422]FNWheels[/MENTION] is releasing its own 8" version addressing the shortcomings (some) customers perceive in the TRD version.
i'm not taking a dump on the TRD wheels, by any stretch. i think they're perfectly fine depending on your application. i'm just saying that i can understand and appreciate that there is a market for the new FN version, as well.