For those unfamiliar with soft takeover, it allows absolute controllers (i.e. non-motorized faders and any regular knob that's not an endless rotary encoder) to work smoothly with your DAW without unwanted nasty jumps which would happen after parameters in the software are modified by the mouse or automation and therefore no longer match the hardware.
At the moment, Studio One only supports direct mapping, in other words, whenever there is disagreement between the software and the hardware, the hardware always "wins". For example, if we assign a hardware knob to control a parameter called "Filter Frequency" and then we change the parameter value with the mouse, effectively causing disagreement between software and hardware, if we then move the hardware knob the software parameter will "jump" instantly to match the value sent by the knob. This jump can result in all sorts of undesirable results such as messing up a mix or an instrument patch. The purpose of soft takeover is mainly to eliminate these jumps. With soft takeover enabled, users must move the hardware knob or fader until it its value "matches" the software, at which point the software parameter starts following the hardware. This, of course, is an oversimplified explanation and I put the word "matches" in quotes because there are many ways to implement sof takeover, some of which can be technically quite involved.
I like the way soft takeover works in Ableton Live. It even shows an indicator on the UI which shows you which way you need to turn the knob to get it to line up with the software, pretty neat. Here's a good video by TheDSPproject:
If you watched the above video, you will notice Ableton offers several interesting solutions to this problem. All flavours of soft takeover will necessarily make some compromises, letting users choose their poison, as it were. I don't use Ableton but I must admit I'm a bit jealous of the way it handles absolute controllers compared with Studio One.
I do use, however, NI Traktor for DJing, and it also features soft takeover, and I really like the way it works. I would encourage Presonus devs to take a look at Traktor. It allows users to assign multiple hardware controllers to the same parameter, and soft takeover still works. Furthermore, soft takeover is a per-assignment option, not a global option, which is very flexible. If Studio One ever gets soft takeover and it is per-assignment, it would probably be a good idea to let users specify in the global preferences whether soft takeover is on or off by default for new assignments.
In summary, I believe soft takeover would be an addition welcome by anyone who owns a MIDI controller, which is probably 99% of Studio One users. Thanks!