[Amps] Amertherm circuit protection thermistors as a soft start - good or bad?

[Conrad PA5Y]

   I have just acquired a GS35B PSU. It is 3 phase and the schematics show 3 x
   NTC thermistors in series with each primary. I presume that these are some
   kind of soft start. I am not familiar with these devices but they make me
   uncomfortable, I have always used a series resistor that is shunted by a
   relay after a few seconds in the past. I do not have the model number of the
   devices used as I will need to open the PSU to find out what they are but I
   assume that they are similar to this device.
   [1]http://www.ametherm.com/datasheetspdf/MS325R020.pdf
   The resistance varies depending on the load current and they get hot in
   order to operate, this really puts me off. They have quite a long time
   constant so I am uneasy about them altogether.
   Should I be concerned and replacing them with a soft start for each phase?
   Apart from that the PSU is very nicely made and will provide up to 1.6A@
   3600V.
   Regards
   Conrad PA5Y

References

   1. http://www.ametherm.com/datasheetspdf/MS325R020.pdf