The X300 series isn't a garden tractor, at least not in Deere's lineup, even though it has a stouter frame than garden tractors of the other brands right now (including the Sears/Husky GT twins). You need to get into an X500 with the thicker hitch materials before Deere considers it a garden tractor (in which case you get other features like locking diff, etc). It's just the way Deere has their lineup arranged. But when you think about the fact that the X300 series and X500 series share the same frame construction except for the hitch area, it's obvious there is some overlap.
BTW, I don't like the K46 regardless of how you classify the tractor, and think it's unfortunate Deere uses it in their entry level X300 models. However, that transmission is fine for some applications, like mowing flat terrain. It's really hills and heat (from extended use) that kill it. Unfortunately, buyers (of all brands) don't usually know what limitations they're getting with a K46 machine.
At least in the case of the X380, which is the general machine getting compared here, the engine (Kawasaki) and transmission (K66) are the same, it's the availability of locking differential that differs. I am pretty sure the engine/trans combo are the main reason these models get compared, which is probably misleading.
In every comparison we have here on TBN, pricing is the general gripe people have with the Deere models, and I won't hold that against anyone. But at the time I bought my X380 in early 2016 it was just a few hundred more than the Husky GT52 model (same exact machine as the GT48 discussed here except for deck and differential). For that few hundred dollars the Deere had very compelling value. Even at $1000 more it had compelling value. I compared those two machines (and the Sears twin of the Husky) very closely over a period of a couple months before coming to that conclusion. The calculation would have certainly changed if the GT48 was available, but I still see quite a bit of added value in the Deere, so it would come down to what it's worth. For me, the nicer dash/control layout, real gauges (including fuel gauge), significantly better seat, and beefier frame on the Deere are worth something. Getting ~ $700 knocked off helped a lot too.
Right now the current Husky/Sears GT lineup dates to about 2012 (engine/transmission/diff options notwithstanding). It will be interesting to see what they do in their next redesign, but I have no idea what their timeline is for that. Deere made some nice improvements for the 2016 redesign when the X380 was introduced, but it's their market to lose if another player can come in with a similar machine for less money.