I’m not a big fan of them in general, and I can’t remember ever using an actual sampled loop or phrase, actually… I’ve used Action Strikes and VPS Avenger sounds with arpeggios at times, but usually it’s like with synth presets; I either modify them, or make my own from scratch.
Obviously, the main reason for this is that I don’t want to use instantly recognizable loops, phrases, or sounds, especially not if they have a lot of personality, as it can become something like the musical equivalent of a photo collage.
Another motivation is that I want to fully understand the feel and expression of anything I put in my compositions, and thus, I kind of have to learn to actually play it anyway.
Of course, with a good ear and training, it shouldn’t be a problem to “reverse engineer” phrases to play along with them, but that takes us to my third motivation for not using phrases: I usually already have a clear idea of what I want to do, so trying to find phrases that fit that would be difficult and backwards.