Are paper revision services worthwhile?
[paper review service] reduced [paper] size by more than 50% by taking out words phrases that they thought to be redundant and rewording sentences to be easier to understand by anyone.


A fifty percent reduction in paper length is an excellent improvement of your paper, because your readers have less to read. (Assuming what "they thought to be redundant" really was.) There's no need for any "sour feeling," appreciate the improvement and learn how to make similar reductions. (Note that reductions are far easier for someone else to make than the original author.)