K&R isn't that terrible when code is neat and clean, but it starts to have trouble IMO particularly when declarations or conditions wrap to multiple lines. Compare the following examples... I personally have to stop and read the code to find the blocks with K&R braces, vs being able to see them at a glance with Allman.

    void MyLongMethodName(SomeLongParamType param1, SomeOtherLongParamType param2,
        YetAnotherLongParamType param3) {
        if (longContrivedVariableName1 == longContrivedVariableName2 && 
            longContrivedVariableName1 != longContrivedVariableName3) {
            // do stuff
        }
    }
    
    void MyLongMethodName(SomeLongParamType param1, SomeOtherLongParamType param2,
        YetAnotherLongParamType param3) 
    {
        if (longContrivedVariableName1 == longContrivedVariableName2 && 
            longContrivedVariableName1 != longContrivedVariableName3) 
        {
            // do stuff
        }
    }

Emacs autoindent to the rescue:

    void MyLongMethodName(SomeLongParamType param1, SomeOtherLongParamType param2,
                          YetAnotherLongParamType param3) {
      if (longContrivedVariableName1 == longContrivedVariableName2 &&
          longContrivedVariableName1 != longContrivedVariableName3) {
        // do stuff
      }
    }

IME the more complex your code formatting, the less likely people are to do it, especially after your code has been touched by dozens of different people with a dozen different editors.

This is why emacs is the One True Editor ;-)

I treat the parentheses the same way I treat the braces:

    void MyLongMethodName(
        SomeLongParamType param1,
        SomeOtherLongParamType param2,
        YetAnotherLongParamType param3
    ) {
        if (
            longContrivedVariableName1 == longContrivedVariableName2 &&
            longContrivedVariableName1 != longContrivedVariableName3
        ) {
            // do stuff
        }
    }

I also make liberal use of temporary variables:

    void MyLongMethodName(
        SomeLongParamType param1,
        SomeOtherLongParamType param2,
        YetAnotherLongParamType param3
    ) {
        auto condition1 = longContrivedVariableName1 == longContrivedVariableName2;
        auto condition2 = longContrivedVariableName1 != longContrivedVariableName3;
        if (condition1 && condition2) {
            // do stuff
        }
    }

Vertical space is allocated to the actual parameters and conditions, and the extra syntax-only lines exist only to separate chunks. This works well with "paragraphs":

    void MyLongMethodName(
        SomeLongParamType param1,
        SomeOtherLongParamType param2,
        YetAnotherLongParamType param3
    ) {
        auto condition1 = longContrivedVariableName1 == longContrivedVariableName2;
        auto condition2 = longContrivedVariableName1 != longContrivedVariableName3;
        if (condition1 && condition2) {
            // do stuff
        }

        auto someData = buildSomeData();
        doSomethingWith(someData);
        while (someCondition) {
            // loop
        }

        finishUp();
        return someData;
    }