Collection carts - need help

[Herm]

I am not sure if I am using the collection cart correctly. Need some tips from people.

Stone Grinder - I used it in ore mines like black iron/meteoric. The mining collection speed slightly faster then using my enhanced yellow iron hammer but the Stone grinder move so slow that it cancel out the benefit of the mining speed. I don't feel any improvement of using stone grinder. Note that I bring a wagon to help carry load and carry the collection cart. The collection cart also have extra space to carry some load but I always dump load in the wagon when it gets full. My overall time with iron hammer faster still faster.

Reaper - I made this for grass but the reaper collect mostly wild flower instead, which sucks. I need grass way more then wild flower. Using my yellow enhanced sickle get my way more grass from the same bushes. I tried using the reaper to harvest crops from the fields but it feel way slower then the two-handed sickle because the reaper move so slow with the turning. The only good thing is that it can store more but I normally attach myself to the cart to collect and have safes nearby to dump load. My overall time with two hand sickle is faster.

Saw - Didn't need any lumber, so didn't try it yet.

These collection cart is so expensive to unlock and and it doesn't help reduce my time to gather stuff. I am starting to think that that I am not using it correctly. I was so happy when I manage to unlock them but the results are disappointing. They are also annoying to use because the turn speed is so slow.

Anyone know the correct way to use these collection cart? If i am already using it correctly, why are they so expensive to unlock in the first place?