I'm not so sure the plastic gear issue is that big of a deal. I crashed the cutter on my G0704 and wrecked that gear one day, but the biggest issue was they weren't in stock for a number of months. When they finally were, I bought three and told my friend with the same mill to buy at least one. Of course, now that I have spares I haven't wrecked it since. It was easy to change, too.
If something has a sacrificial gear of that sort, just make sure you order an extra when you buy the mill. Or, you could consider a G0729 for about the same price (and it's made in Taiwan so the quality is supposed to be better.) For a bit more you can get the larger version of that one, too. Then you've got an actual knee unless you want/need a benchtop mill.
Grizzly's customer service has been outstanding when I needed it, but I don't think you'll really get much help making a decision. They sell a zillion things and never seemed *that* well informed about anything I ever asked about. Users (like us) are way more on top of it.