Consumer Reports talking about Apple:

The company scored far higher than the other big companies for the elements that make for successful online and phone support: ease of contacting staff, clarity of advice, technical knowledge, patience, and time for follow-up.

And here is what they said about Windows-based companies:

Clearly, there’s room for improvement in tech support: 24 to 40 percent of respondents who sought phone or online help from makers of Windows-based computers said the staff’s patience, knowledge, or clarity was fair at best.