You will likely get a half dozen different answers based on individual interests and perspectives, which is good, but I’m going to throw this out there merely as an equalizer to avoid confusion.
It all comes down to what you really need. The MXT500 has a lot of attributes that make it an attractive upgrade to the MXT400, and it obviously lacks some features that the KG-1000G has, but what it comes down to is what fits you.
The MXT400 gets a lot of flak for its lack of features, but imho unfairly so, because it was designed at a time when GMRS wasn’t as widely utilized as it is now. It didn’t have a lot of bells and whistles because many GMRS operators didn’t need them at the time. Believe it or not, this is still the case for some.
The MXT500 just came out, and for all its upgrades, it’s still getting some criticism because apparently those improvements aren’t enough. Even the KG-1000G, for all its innovative functionality on the GMRS, still isn’t enough for some GMRS users. The truth of the matter is, no matter what comes next, it will never be enough, and there will always be someone who will put it down for that very reason.
We offer a variety of GMRS radios, both Midland and Wouxun, and we do it for a reason. Sure, we do think the KG-1000G is the top choice for GMRS, and we recommend it a lot, but we also realize that it may not be the best choice for everyone. If the radio you buy isn’t the best fit for your purpose, you’re going to want to send it back, and that doesn’t serve anyone, not you, and not us. That’s why we offer multiple choices, and why we don’t just sell radios, we sell the radios that fit you.
There are going to be some GMRS users who will say that you have to get this model, or the other one is no good because it doesn’t have this or it doesn’t do that. That may be true for them, but it isn’t necessarily true for you.
For instance, I work with many of these radios on a daily basis, as it’s what I do here. But when I’m using it at home for personal or family activities, that’s what I use it for. It’s not a hobby for me, it’s a utility, and although I may sometimes get on a local repeater or two for kicks, I primarily use my GMRS license for practical purposes. And I am not alone.
So to answer your questions fairly, If you have the MXT400 and you are happy with it, There is absolutely nothing wrong with that at all, because that is what works for you. If you want to upgrade to something with higher wattage, the Midland MXT500 and Wouxun KG-1000G are both a good choice, as they are both premium radios, and it really comes down to just a couple of considerations, purpose and price. If you are using it outdoors in the open and need something that is more compact and waterproof, go with the MXT500, as the higher price does deliver that perk. If you don’t need the extra waterproofing but want all the features, the KG-1000G is going to be the better value for the price.
Then again, if you don’t need the extra wattage but you do need both dust and water resistance and the premium features, there is yet another option that is a great value for the price, the Wouxun KG-XS20G. it is also quite compact and rugged, but has many of the high end features found in the KG-1000G, and more than the MXT500. Sure, it’s only 20 watts, but the extra power of the two big boys isn’t necessarily going to give you that much extra coverage, and you can compensate for a lot of that with a good, well positioned antenna.
Regardless of the price difference, imho, comparing all these models, the better choice is the one that you feel works best for you.