[Aquarian Sports Cards]

The second half isn't opinion to me. The first half is troublesome to me more in the negative than the positive example from Bigfish's post. Though even "I have had issues", is more problematic than "I had no issues." You can't elucidate on the positive experience. "What kind of problems didn't you have?" isn't really valid. Once you venture into the negative though, some explanation is warranted. Though it can remain completely factual.

"He took three weeks to ship."
"He pulled a bait and switch."
"He said my mother dresses me funny."

Would all NOT be opinions, merely reporting on the facts of the transaction. but a blanket, "I had issues" probably needs clarification if not a name attached.