I'm used to using reseller hosting which isolates things better, but that was more of a niggle than anything else.
But it tends to feel slightly sluggish, and I think their anti-bot stuff catches some monitoring stuff too which triggers a few false down alerts (which again is a niggle, but leaves you with doubts).
(to be fair to them, it's not like I've told them or asked if I'm on a busy node or anything!)