I too have been using the Salice soft close for years. I would also do half soft close and half self close to save a few bucks. I did my own kitchen 2 years ago that way. After about a year and a half, it seemed the soft close function was no longer working. I switched all the self close out to soft close and they are working right. My suggestion is not to use half and half unless the weight of the door is low.
Two other points. One, Salice offers a depth gauge to determine if you are drilling deep enough. For those not aware, the soft close do require the hole to be deeper than self close. If not deep enough, the hinges bind and do not close properly.
Two, the hinges usually are shipped in the open state in the box. I found on Accuride soft close drawer slides if the slides were separated as box and cabinet members, the soft close would have an open memory and would take some time to change the memory to closed once the members were reattached and put in the closed position. I wonder if the Salice hinges may have the same memory characteristic, especially in colder temperatures.