Oh, yeah, by the way, you CAN fix those softspots that they will never come back again.
Once you have cut out and replaced the soft subfloor, you now lay a layer of 1/4" luan over top of the floor and put down new vinyl or new carpet. You simply glue and nail down the luan and that added layer reinforces your floor. Yes, it adds 1/4" to the floor height but it should be no issue. You do not have to laydown the extra layer under cabinets or any other immovable object. Only needs to be done where you walk.
These things can be fixed much easier than you think.. That is a weekend project and if you are slow at it perhaps a 2 weekend project.