We just posted SP1 Beta3 to the beta testers.
We had a couple extra 3rd party bugs that needed to be fixed ( animated parts, mouse rects on the panels, lighting ) that we needed to fix and in fixing the stutters with the first round of threading code we lost some perf and had another bad bug lurking in there. And we identified an issue with 3 AI aircraft, 1 of which is fixed in Beta3 - if that aircraft passes muster in Beta3 we will fix the other 2.
We hope Beta3 shows these all as fixed. That does mean we have lost April for SP1. So we are into May now.
As far as how long it’s taken us, it has been longer than we thought and would have liked. Back in January, we clearly thought we had time in front of us. Just not as much as it has taken. We did hope the multi-core work would be done a good 6 weeks before it was. And the beta tests, while valuable, have added their fair share of the "extra" time. We have found and fixed a couple extra 3rd party bugs that we think are going to be of good benefit to the community because of that time investment.
So that was time well spent. As was the performance and thread bake time.
It is what it is; we are trying to get it right. That does take time. And we believe the result will show that care and attention to detail.