When used properly, personality-type indicators like BEST and DISC are useful for hiring. However, they are not predictive indicators of performance, but only confirming indicators.
A few weeks ago I argued that Time magazine's cover story about using prehiring personality assessments was flawed. In this post, I'll prove it. To participate in the proof, you need to answer these two questions and then plot yourself on the BEST Personality Indicator below. 
Horizontal axis--Speed of Decision-making: Are you fast or slow when making decisions? If you're more patient and like lots of data and lots of time to decide, you're on the left. If you'd rather make quick decisions with limited data, you're on the right.
Vertical axis--Results vs. People: On an important team project, are you more concerned with the project results or the needs of the people involved? The most results-oriented people are at the top and the most people-sensitive are at the bottom. Plot yourself on both axes to determine your dominant personality style. Then read the following descriptions. If they're reasonably accurate, you can see why personality assessment tests are flawed, i.e., they're just too simple to be taken seriously.
The Four BEST Personality Types
Boss (impatient and results)
These are people who are driven and results-oriented. They are dominant, frank, make quick hiring decisions based more on intuition than facts, and at times can be perceived as heavy-handed or overbearing.
Engager (impatient and people)
These people are typically extroverted, friendly, and persuasive, possessing the classic salesperson persona. They quickly decide whom to hire based on first impressions.
Supporter (patient and people)
These people are the consensus builders--HR people, diplomats, and counselors. When hiring they look for people who "fit" with the organization and are team players.
Technical (patient and results)
These people are the classic process-driven analyzers and techies. They tend to focus on experience and technical expertise when making hiring decisions.
While this simple DISC-like personality test is a reasonably accurate assessment of personality style, it doesn't demonstrate your competency, just your preferences. Nor does it demonstrate your flexibility to move out of your comfort zone based on the circumstances. Worse, your answers can easily be faked. Bottom line: They prove nothing from a prehiring standpoint. But these tests are not useless. They do have value when used properly. Here are some ideas.
Determine if the candidate is becoming better at his/her BEST personality style. As you ask the most-significant-accomplishment question about the person's past few jobs, find out how he/she made decisions and dealt with conflict. As people mature properly, they take on the traits of all of the styles, essentially moving to the center of the grid. This is the coaching position. Movement away from the center is of concern, since the person is not showing an understanding of how other people grow, develop, and communicate.
Become a more objective interviewer by becoming your least BEST. People are more comfortable with those who are similar to them. This includes their own dominant BEST style and the two adjacent styles. They tend to have the most conflict with their least-BEST style--their diagonal opposites. You can improve your interviewing skills by adopting the traits of your opposite style. For example, a Boss can be more objective by becoming a Supporter--slowing down and listening before judging.
Determine the candidate's BEST style flexibility. As you dig into a person's major accomplishments find out how he/she handled situations that called for different BEST personality styles. The most adept people are able to adjust their dominant style to meet the needs of the situation. For example, a Technical should be able to collaborate with people in all functions, i.e., become Engager-like, to determine product requirements.
It's best to use BEST-like tests as confirming rather than as predictive indicators. Personality tests like BEST, DISC, Predictive Index, and Calipers focus more on how work is performed, not the quality of it. That's why they should never be used as a predictor of success or to screen out people. It's certainly appropriate to determine a person's work style after he/she has been performance qualified. BEST and similar personality-type indicators have their good and bad points. Since you can figure out your BEST style in a few minutes, and even the not-so-clever can fake it, it shouldn't be used for filtering out people. That's why I took issue with the Time magazine cover story. However, from a hiring standpoint it can be used to make better assessment decisions on two fronts. For one, the interviewer can become more open-minded and objective by collecting information using the BEST techniques of each style. For another, during the interview observe how candidates have modified their styles over time and if they modified their style depending on the circumstances. Some people are more flexible and others more rigid. When used as part of fact-finding this way, a BEST style assessment can help the interviewer better understand a candidate's flexibility, cultural fit, personal growth, and ability to work with and manage others. That's why BEST is simply the best personality type indicator for hiring anyone.