I had a soft roll-up tonneau cover. While it didn't leak, it shrunk in the colder months and expanded in the summer. So you have to set all the snaps in the winter position which is closer or the summer - farther out to compensate.
Taking it off to use it was a pain. Especially if the cover had shrank which caused me to re-position the snaps in order to get it back on.
The worst thing that happened was that the cover rubbed the paint off the cab where it was in contact with it - just above the rear bed rail.
Would not do a soft roll up cover.