Your voice is central to your identity. It is your individual means of verbal expression. Even on paper it must be distinguishable as yours and maintain its authenticity. Having your work edited shouldn't mask your voice but rather respect it, and allow it to come across more clearly.
Assimilating information from poorly written material takes a degree of effort on the reader's part – it is the equivalent of a bad journey: bumps in the road, a circuitous route and multiple distractions.
copycopia will iron out any bumps in your text to facilitate smooth, fluent reading.