After experiencing this in Express the last few sets, I have a few thoughts

1- I like it so far, and surprisingly, it's NOT too hard to do quick DR estimates in my head. People with scripts doing estimates for them (alliances will probably make these) will have an advantage, though probably not a major one.
2- For Express, specifically, the 8-hr DR makes DR a bit shorter *in most cases*, which is a good thing, because 24 hour DR in such a fast-paced server was long.
3- In some cases, and this is an Express issue specifically, DR can now last *longer*. If, 48 hours in, someone does 100 GS on a country, that country will be in DR the rest of the set (72 hours). I recommend lowering the amount of time before DR is totally cleared for Express, since it has a shorter DR half-life and is a faster speed server.
4- Team is also a faster server, but has the same 18 hour half-life base as the slower servers. It should definitely have a shorter, customized DR half-life as well (but then, Team Server has other problems as well).
5- In Alliance, Primary, and Tournament, I think the 18 hour half-life may also be a bit too long. This I don't have experience with yet, so I guess we can wait and see, but I predict countries getting stuck in the 4-5 DR zone, and staying there long-term. Before DR was gone after 24 hours, now it's still 50% there after 20. That's a lot more DR...