The nation that spawned the Galil, the Uzi, the Tavor and the Desert Eagle rates an "OK" record?
Exactly, they are OK firearms, they are not great and they are mostly secondary in their designs. It's not a bad thing - to use proven designs, it's actually a good thing, however it is different from having a rich history of firearm development, like France, Germany, UK, USA, Austria and so on.
The RDB design is deeply flawed. The barrel is the spine of the rifle, which is a mildly interesting idea but has the problem of the steel barrel expanding with temperature at a different rate from the aluminum scope rail. Take a look at the pic rail and you'll notice the rear screw hole is oblong to allow the rail to slightly float on the barrel mounts. That is not what I'd call a "sane" design.
I am aware about barrel being a main part that holds everything together. However you contradict yourself - you say there's a problem and you point out how KelTec engineers solved this problem. My RDB did not have any noticeable drift as the barrel was heating up. Solution worked.
Not being able to see the chamber and the rifle essentially needing to be partially disassembled to clear a jam in the chamber is a very serious problem for any rifle. Especially one that can easily have the gas system adjusted down to the point where double feeds can be induced. This is not better than the Tavor. It is demonstrably worse.
It's a quite a l flaw for military rifle or competition rifle. It's not a problem at all for sporting/plinking rifle. So its design works just fine for intended purpose.
The RDB gas system is open to being grabbed when it is hot, which will result in a serious burn. Also not better.
Not having adjustable gas on modern firearm is a huge con in my books. Ideally it should have only few positions (cut off, supressed, normal, adverse). 20 positions of RDB is overkill, zero adjustability on X95 is stupid. All military designs without adjustable gas block are over gassed, because this is the simple way to deal with potential issues. Gas bleeding is better solution, but it has its own limitations.
Also I don't agree with your logic. A) Barrel also becomes hot, but it's not a problem? B) Adjustable gas system should have accessible gas regulator. You can't have both hidden and accessible at the same time. Think Bren 2, ACR, XCR. In many designs there's a slot or hole so cartridge or bullet can be used.
Guess what the manual shows about RDB gas adjustment? As if they knew something
The RDB magazine release is interesting but it is not better than the more intuitive release on the X95. It is also much slower than the X95 because it requires the same hand that could also be holding a new mag waiting to be inserted.
Right hand thumb to engage mag release, left hand is grabbing new mag. Just different manual of arms.
I liked my RDB until the trigger went south and required a pretty expensive repair. I also sold my RDB and kept the X95.
Trigger was a design flaw that they resolved. I recall you had same issue as me - doubles. Newer gen trigger doesn't have this issue.
I don't hate the RDB. It's an interesting rifle and I kinda liked it. But it is in no way the equal of the X95 as a whole package. The RDB has a few features that are better but as a package it is beaten out by the X95.
Of course they are not equal. My point was to say that X95 has outdated design with quirks, and low accuracy and some other flaws, but highly reliable and RDB is more modern design, very accurate, but of lower quality and doesn't have highest reliability. But we all have different purposes for firearm. For my purpose X95 works better, but I can easily see how RDB would work better for most of CGNers.