I've used speedfan for evaluation and it works fine, but my laptop doens't have a separate fan sensor, so I can't control the fan with it. Running it with anotehr program for Dell laptops that *can* control the fan, however, the temp readings are usually very close to the same. So I like it, yes, and I run it to verify the other program's readings.

Speedfan has pretty good documentation, too, and I've used it on my last three computers.