There are some good suggestions in this topic, should be highly considered.
I might be the only one disappointed a bit with the upgrade rates. If I recall well, first Shard +8 was upgraded in less than 48 hours in the current DB.
It's not about +7 or +8 upgrade rates but until this point, upgrade rates are too high (100% until +3, even +7 with trina is 25% is pretty high). I don't know about the rest but I'd prefer to see +8 items rarely. I'd love to see people having pk with +5, +6 items.
I did not hear anyone complaning about upgradable item drops (except some comparing mini dm vs. dm drops etc.) so people can farm items considerably good. Trina and BUS farms are not that hard and supported with the hunt quests. If they will be kept as the same, then upgrade rates can be decreased to make server more challenging.
My suggestion for BUS only upgrade would be;
+1 --> +2 = 80%
+2 --> +3 = 60%
+3 --> +4 = 40%
+4 --> +5 = 20%
+5 --> +6 = 10%
+6 --> +7 = 5%
+7 --> +8 = 2%
Rates with Trina can be;
+1 --> +2 = 100%
+2 --> +3 = 80%
+3 --> +4 = 60%
+4 --> +5 = 40%
+5 --> +6 = 20%
+6 --> +7 = 10%
+7 --> +8 = 5%
Of course rates can be adjusted as needed, they can be even lowered more. Main idea behind this suggestion is to decrease all of the upgrade rates (not only keeping +7 or +8 low). We all know that Anvil is addicting, whatever the rates will be it won't stop people to try upgrades.
When people have challenges to keep them busy (in this case upgrade), they will less likely to ask for BF, Juraid etc. expansions. Overall it can increase the lifetime of the server.
Regards,