Well, if you're only going to be using 1 interupt source, it will be better without DT_INTS since you don't need to test for which interrupt was triggered.

I just did a quick test with an incrementing variable and a SIN lookup with an 1827 running at 32Mhz.

With DT_INTS ... max = 140Khz
Without ... max = 220Khz

With 2 interrupt sources the difference is not as pronounced since it has to check which one triggered and jump over the handler that wasn't. DT_INTS always does that.

The PWM will have to be running much faster than the interrupts or it will be changing dutycycles before a single cycle has completed. Could be trickey.