This specific build (7666843) is often associated with the post-launch patch that fixed several bugs in Weapons Drawn (improving the "Find the Safe" logic and performance) and polished the localization. In this context, the "solid feature" is the stability and bug fixes provided by this specific update. Ares Sdpa Pthc [FAST]
It sounds like you are highlighting a specific release of (Build 7666843). Api Rp 2fb Pdf Link
If you are referring to the aspect, you might be talking about one of two things:
The "solid feature" of Jackbox Party Pack 8 is that it maintains the series' standard of supporting 8 active players (up from the 5-player limit of older packs), plus an unlimited audience. This "solid" player count makes it one of the best packs for larger groups or streamers.