If X10 sold the XTB-IIR to the public, they would regain significant market share as it is THE solution to signal issues. The only other way X10 could make their systems as reliable would be to have each module act as a repeater. However, that would certainly have significant cost implications per module, so may not be the best option.
Completely agree on the XTB-IIR! And yes, if every module could act as a repeater and if they could pack in some of the firmware additions that ACT used in their A10 line such as the extended addressing, status reporting, and programmable options, they would have something that could compete with Insteon and still maintain the backward compatibility with older X10 that Insteon used to boast, but without having to design and program for 2 different protocols. It would still be slower and a little more susceptible to interference than Insteon, but it would be close. But you're right; it would raise the price significantly. And at that point, even if they had similar prices to Insteon, what's the motivation for a newbie to choose a similar but slower and older technology over a more modern one?
I think that Dave Houston's idea of building in out-of-the-box Arduino-compatible features is a winner. It may not significantly stimulate the market for commercial products using X10 but it would give hobbyists a reason to buy X10 modules by the truckload instead of other products. The thing about home automation standards right now is that there are so many of them. If one platform can be more compatible with more of those standards, especially if one of them is a trending platform for hobbyists, it will stand out. If I had a choice, I would of course want all of the above -- built-in repeaters too.
Edit: Changed "Android" to "Arduino" (which is what I meant!)