正点 has two common, distinct uses. One is 'on schedule; punctual' — you'll hear it for trains, planes, or events that run exactly on time. The other is colloquial slang meaning 'great; awesome; spot-on' — it's often used to compliment someone's appearance (她真正点 'she's really stunning') or to praise something's quality. The slang sense is informal and most common among younger speakers.