Will fénix 5X plus get fénix 6 interface?

Some features will come and have come. Others will not. 

Typically in software a GUI rewrite doesn't port to previous versions of a product.  I could get into the reasons but ultimately you shouldn't expect it. 

I would like to see this as well. I have a 5 plus not 5x plus but would still like to see some the UI changes. But it seems that Garmin doesn't add any features to old devices in order to get people to spend money on the new products. 

What do you day have come? I cannot see any new think added in the watch software that can be find in the new 6, am I missing something?

The question on the title is should be what you would like to see ported to the 5x from the 6.

I know Garmin is not good updating old models with some of the newer features. They focus on the new releases and mostly bug fix the old. But still it will be a very nice gesture to port some things to the old ones. They have done some in the past.

That’s a bit harsh. The 5+, like all Garmin watches, gets new features added for a while after launch. What you should not expect is the application of all the features that come with new hardware, most of which probably cannot be back ported.

I think it’s a huge stretch to say that “most of [the new features] probably cannot be backported”. There is absolutely zero reason that Garmin couldn’t make Training Focus metrics or the new Watch Faces, for example, available for the 5+ and almost certainly some even older devices - even if only through Garmin Connect.

There will, of course, be new features that require the 6 hardware and clearly no one is expecting those to be backported. But my reading is that the vast, vast majority of new features of the 6 aren’t device features at all. They’re simply software updates that could very easily be released to other devices; in a similar way to the Apple Watch for example. Or any number of other consumer electronics devices; whether it’s Apple or Android phones, laptops or even cars nowadays. 

Now, it’s Garmin’s right to choose to withhold those software developments from existing customers. But they shouldn’t be surprised when customers get disillusioned at new devices being released with no real hardware innovation as a selling point but only software features that they are asked to spend substantial sums of money to get access to. So Garmin may sell a few new devices off the back of them, but I wonder how many repeat customers they lose as a result.

I don’t think it’s coincidence that having initially not gotten the Training Focus feature when it was released on newer devices, Garmin has subsequently released it for the Edge 1030 - a device for which there is a genuine competitor in the Wahoo range of bike computers. There isn’t a comparable competitor in the watch space yet, but if one comes along then Garmin may well face similar pressure to keep their loyal customers loyal. 

One significant thing here is the fonts on the f6 are different than the f5+, and to switch to the f6 UI, the font would likely need to be changed on the f5+, and that would break a ton of f5+ CIQ apps. 

Also, there's licencing involved for features, like all the features using firstbeat