Here is my experience:

I have played for a long time and at the moment we usually do 200/300 areas run on ghostbeard formation to farm idols.
I have used 40 min stacked buffs (from uncommon to rare) and only gained 20/30 min in total.
This buff is neither a long term solution to farm nor to achieve a hard mission, the previous buff was much more effective to achieve hard mission ,especially 350 boxe mission with a good rush strategy (stacking click buffs). I think it is impossible to achieve this mission with less than 15k idols now.
If u created this speed buff it was possibly to achieve the 80 timed mission and the 45min carnival achievement but time warps are more than enough and more effective.

I suggest other options:
-increase the duration of the speed buffs
-go back to the previous click buff
-another "usefull buff"?

Hi Justin ! Thanks for the constructive reply. I'm very happy to hear the developer intent on the buff and how they consider to change it in the future. Looking forward to it !

Hi Justin: About the 4 answear the buff you removed. It was the strongest one. Using diffrent rarities could make your clickdmg 2x-4x your dps.. The buff you saved is not even close to that... All give u what like 30%?

You made it 10 times harder to do the hard objectives now. Ruined my 350 run.

Well there is cases when that buff is bad, and its called emo.

Regarding the issue of loot pickup, my first thought when I noticed this was that, instead of "enemy spawn rate", this buff should be re-characterized as "increase crusader walk speed".

My reasoning is: if you de-gamify what's happening - that is, instead of the enemies being creating out of thin air (i.e. "spawning") - what appears to be happening is the crusaders are marching on their quest and, while doing so, are continuously running into enemies that already exist, but can't be seen until the crusaders have advanced far enough (which you could regard as the concept of "range of vision" of the crusaders; as an aside, if you wanted to introduce a new crusader down the line that has the unique talent of increasing spawn-rate/walk-speed, you could explain it away as a result of his sharp vision (you could make him a lookout or sentry or sharpshooter, or something, or even some animal with extremely powerful vision, like a falcon/hawk/eagle)).

Therefore, increasing walk speed corresponds to enemies "coming into range" sooner, which achieves the same result as an increase in spawn speed. Furthermore, since they are walking faster, they will automatically be reaching the loot faster, so the game mechanic of "automatically picking up loot when the foremost crusader in the formation reaches it" already takes care of the rest, without you having to "look at adding an "auto-pickup-quest-items" effect to this buff" (which I'd guess might be problematic, in terms of bloating the block of text that describes the buff to the players).

Finally, to mention something that's more in the bug category, I've noticed that the icons for the different rarities of the new spawn-rate buff (it might happen with the other buffs as well, but I haven't notice that yet) collapse onto each other (that is, even though I'm still receiving the 50%+50%+50%, for example if I'm concurrently using the white,green, and blue versions of the buff, I can only see the blue one, presumably because the others are placed directly behind it). This doesn't always happen, but I wasn't able to figure out what triggers this collapse.

Hope this feedback proves useful to you guys.