I also wouldn't be at all concerned about buying from Hats Direct (also have the Heritage Campdraft), no issues.There are custom hat makers that can make you a nice hat for a very similar price to the Nostalgia - check out Falcon Park Hattery for example. Bowlerman, here on the forum just received a super hat from the Falcon Park guy - do a search and you'll find his pics. Bowlerman's hat has that tall crown 30's look as do the hats I have from Tumwater Hat (a little more expensive, but really good value, I'd say!)
Also, in my opinion, the Federation IV is a way better hat than the Nostalgia was and tons of people here have purchased from Hats Direct with no problems. I haven't bought from them personally, but I bought a Campdraft hat from Everything Australian with no issues.
I'd say you have plenty of options if you want to get a new hat.
As to how the Fed IV compares with the Nostalgia, I can't say as I've never handled (or seen in person) a Fed IV. But some threads I've read here comparing the two directly have led me to believe that they are fairly similar (at least in profile/dimension). Presuming their felt texture is the same as my Campdraft (Heritage grade) and Camp Draft (Imperial grade), I'd say the Stetson has the edge in the hand of the felt. Might not be as durable, though it seems fine from a quality point of view. But the felt is maybe just slightly softer (it may be my imagination, just stroked each as I write this, and they are quite similar). I think either is a great option.
Being as the Fed is available, currently made and in a few more colors, that's the way I would go at this point (unless you can find a Nostalgia for less and/or it is the color you'd want).
Would you be a 7 1/8? I've called at least once a month since getting my Caribou Nostalgia, they've had black (which I now wish I'd bought!) but not Mink (brown). Haven't even seen a picture of a brown one anywhere yet.I agree wholeheartedly on the Nostalgia. Mine's not my favorite hat- my '63 Open Road holds that honor, but the Nostalgia is a close 2nd.
I call HatCo every few weeks looking for a brown one in my size. I love 'em.