I have another perspective, and that is because clients call us knowing that they are paying for our time and expertise.
For lots of good reasons, we are busy these days, so we start with talking to the client to get as clear a picture as we can. Most clients choose to have our LogMeIn client installed, so we often have joined them on the subject machine before they are done telling us what they are experiencing.
Sometimes the solution is quick, sometime it is involved, but the effort is collaborative until we get to a point where the client can't help us any more, and we have to dig.
When it is a familiar issue for us, we can get it resolved in 15-30 minutes and get them productive.
It comes down to our model is different, we deal with all kinds of different aspects of the client environment, and we tend to work holistically versus step-by-step.
YMMV
