That's a great recommendation. IMHO, the single most important factor is having a good supervisor. A professor that has placed a significant proportion of his students at tenure-track jobs indicates that the research group is probably healthy and supervision is good, with high quality publications and support.

The opposite, postdocs that never publish and get stuck or leave academia one after the other tends to signal dysfunctionality and is a big red flag. If you dig deeper, those groups are usually broken in a number of different ways and it's critical to stay away. A bad supervisor can ruin the prospects of a great student.