I do not like dealing with ZZP.
You have every right to avoid them and share your opinion of them if you had a bad dealing. I am a strong believer in boycotting companies who have taken advantage of me. I have had good luck with ZZP, I experienced some small imperfections (wrong exhaust clamp size, no screw for custom FMIC temp sensor bung). That stuff is not a big deal and I envision ZZP is a small company without a expensive inventory control system and full-time quality management...I would be much harder on a 50 million dollar company than I would with a 1 million dollar company.