I would say Al Hidayah and Lubab are almost the same, as they are both commentaries of almost the same books (Mukhtasar Quduri and Bidayat al Mubtadi are almost exactly the same). Also, both are four volumes, so each volume should have around the same amount of information. However, Turath is releasing Lubab in two volumes, not four, so this release, in my opinion, would cover what the first two volumes of Lubab would cover (which would be comparable to the first two volumes of Hidayah). Then it would cover the acts of worship, along with many of the hudud. I dont really know, though, as this is all speculation.
As for why they are taking so long, I cannot say. I agree they should speed up the work.