Indeed, R4 effectively meant "Signature Plastics Keycap Group Buy #4", back when there was only one large SP GB at a time. R4 tried to be way to many things at once, while also trying to fix the errors in R3. Yes, there are people with R3 sets from over 2 years ago that are still waiting for replacement caps. It spiraled completely out of control when SP jacked-up their prices and lots of people backed-out.
In the meantime, the entire GB landscape has changed. Now, SP GBs happen all the time and there are vendors supplying us with key sets and novelty keys at will. We also now have QWERkeys, GMK, etc. Remember the "Ragnarok" set (red on black)? That was supposed to be part of R4 ("Blood"), but was dropped by 7bit along with Oranje due to lack of interest. Rag took the Blood idea, pruned it down to the essentials, and sold 131 base sets! In fact, I think the Ragnarok set was the first set to use the now-common ANSI TKL+104+ISO+Tsangan kit concept. The downside of this was that it ditched all of the foreign language packs, leaving non-ANSI users in the cold. Conversely, part of the reason it sold so well was because of the pricing (base ANSI wasn't subsidizing rare language packs). This problem has yet to be solved.
There are a lot of unique things about R4 and it's great to finally see them ship!.
