yes, take them off...mount that flat! IF you ride a lot of park, then it will be loads of help because your center of gravity is lower, making it easier to jib and whatnot. I could tell the difference instantly...so get 'er done
for the park, take them off. it'll be easier to slide rails and funboxes and stuff like that. better at take-off, too. landing will be more solid. for out of park, a lift can be super nice - more edge power!