We're paying customers, not cheering fanboys. And IXEG and X-Aviation are for-profit businesses. We expect a finished product for what is a very expensive addon that we paid for. To put it politely and with full respect to the developers, after 3 and a half years of ownership this state of affairs is unacceptable.
Additionally at this pace of development I'm of the opinion that by the time the FMS rewrite is complete most people would've have moved on to XP12 or MSFS2020. Remember XP10.51 was the last version of XP10, and we're now approaching XP11.50. Vulkan/Metal and the experimental flight models would probably become compulsory by then, and will most likely break this addon in some way.
Developing addons for X-Plane is like running on a treadmill. If you don't update constantly, you're at risk of falling off and not be able to climb back up again. Even with the FMS rewrite complete the rest of the addon might become so old that it is unusable without much more development work. And that work need a monetary incentive. This is why early-access games on Steam often fail, because the money stop coming in soon after release. Unfortunately coming from FSX/P3D I find this trend to be all too prevalent in the X-Plane community.
What I see is great, but squandered potential. When it was released it was the by far the most detailed addon for XP10, despite it being released in an incomplete "early access" state. From a long-time FSX/P3D user I can see that it has the potential to become PMDG-quality if finished, and this was the addon that got me moving to X-Plane. What happened afterwards was that the devs stopped releasing patches for 2 years while the addon is still in a relatively buggy and unfinished state, and customers like me were frustrated at first, and then progressively lost interest. I haven't flown the IXEG for so long that I forgot that I actually still have it, until today when I did some cleaning up of my XP11 installation.
When you charge $75 for an addon, there's no excuse to leave customers with a buggy and unfinished product without an update for 2 years. At least release some quality-of-life patches and ninja fixes that makes their experiences better while you continue to rewrite the FMS. Because if you take too long on the rewrite (or it stalls due to other commitments), you might find that Laminar has already moved way ahead of you, and the rest of the addon no longer works. At least with more ninja fixes the customer would've gotten a bit more enjoyment out of the addon, while you rewrite the FMS.
As I said earlier, time is against them. XP12 will come very soon as Austin needs more money, and a head-to-head competitor to the big MSFS2020 launch next year. Like the move from XP10 to XP11, the vast majority of the X-Plane userbase will move forward with each new release from Laminar. The treadmill is only getting faster and faster......