Okay now before everyone goes "oh Blazing is just whining boo hoo hoo" hear me out. While the return of stone drops is a blessing, it's also a double edged sword due to the combined fact that...
a) Their droprate makes getting them hard.
b) Generally liked farming spots are either taken, stolen, or both.
Now let me talk about their droprate. Back when Daneos first released Mystery Capsules he stated that they have a 10% chance of dropping. Suffice to say, you see these WAAAAAY more often than any kind of stone, which means that each stone has a lower chance of dropping. That is, honestly, a stupid drop chance. In addition, it effects the economy because people will charge stones for a ridiculous amount (a lv70 Red Stone is generally 25kk or so) making it extremely hard for players to get their hands on one. We also need to consider that there are 6 stones and generally the area you farm in drops two levels of stones. That's 12 upgrade stones we're talking about here, and all have a drop rate lower than a mystery item which, again, has a 10% chance of dropping per mob makes it not worth farming for them.
Now people are going to tell me "but Blazing increasing the drop rate will make people more op with upgrading and etc." Yeah, +8 is reeeeeeeeally threatening. I remember in old DBO that people at least had gear that was +8 (weapon) or +6 (armor). In DBOG, it's hard to even pull this off, especially with high level gear. With tickets gone and White Stones getting booted from Cash Shop (and possibly the game) we need a way to collect more stones to compensate for this. A simple +8 is enough for any player to get buy with all but the hardest of dungeons and Budokai, but we're not going to see that happen if players can't even upgrade their gear.
So yeah, that was my two cents on the matter. My suggestion is increase the drop rate of stones (with purple and green being rarer than red and blue with downgrade stones in the middle) and/or add an alternative way for players to get these stones ingame (Budokai, UDs, etc).