The radio looks good; wondering if the Yaesu FT-DX1200 is a major bump, not that big, or am I looking at apples and oranges.
I have a friend with one, it's pretty nice. In a few hours of running it, here're a few things I've noticed.
It's freekin' big, like twice the bulk of a 450, and weights 20+ lbs. It's too much for a car camping trip, more of a shack queen rig. Bug-out bag? Fugettaboutit. The main RF parts are big, heavy, analog RF circuits. It's a triple conversion receiver that shrugs off interference. Lightning crashes and nearby stations aren't a problem. It won't overload like some of the SDRs will.
Having all the knobs and buttons is nice. It's a little easier to operate and tune around than the 450, less cramped. Memory operation is really easy, downright intuitive by Yaesu standards. (OK, that's a pretty low bar.)
The DSP filters are easy and useful on digital modes. Narrow, wide, notch, etc., you can slice and shift out the signals you don't want to pass to the computer. The DNR is effective and has like 10 levels. I think the DSP & DNR are in the last IF; check me on that Carl. It's the replacement for the 950, I think that was last of the old AF stuff.
Tons of menus. Everything is adjustable, maybe too much so. The scope function is fun, but maybe not that practical without the FFT board. Kind of nice for shortwave listening though. The big display is pretty nice, you can keep track of lots more things than on a 450.
My buddy found his lightly used in the mid-$800's, but I've seen them new in the mid-$900's. In some ways it's a major bump from the 450, at the cost of portability. At this price it's probably worth the step up if you don't plan on hauling it around much.