Its a personal thing.
Water doesn't compress so has better feel but some people are paranoid it can damage the brake.
Oil doesn't damage the brake but can compress slightly.
And also.
This will answer your question 20-30 times.
I have to admit they really do look nice.
But it looks a little to thin, you could put a buldge there but it would ruin the look.
Maybe if you but some sort of inbuilt booster from one to the other it would help.