The new muffs are much nicer than the old ones. The front side uses a foam similar to the trail seat bags. It’s stiff and holds the shape well. The closures are now magnet vs the old style Velcro. It makes it much easier to install. The section that wraps around the bar is still Velcro similar to the old ones. Also, it looks like the pin that slides into the bar is a bit larger and seems to hold better so far. The window on top is larger as well, not that it mattered much to me. Overall, I like the new ones better than the old style, they seem to have more open space inside, but it may be due to the front foam section.
You can run the XRS handguards on the outside of the muffs if you wanted to, I tried it and they fit. They will not work on the inside of the muff without some sort of modification to the muff mounting system.
As for being out of stock, I ordered a set at the dealer last Monday and they were there on Thursday.