The perception of sequins being 'tacky' or 'classy' largely depends on how they are used in the context of an event. If used sparingly and tastefully, sequins can add a touch of glamour and sophistication to your event decor. They can be particularly effective for evening events, where their sparkle can add a touch of elegance. However, if overused or combined with other overly bright or flashy elements, they can come across as excessive or gaudy. It's all about balance and knowing your audience's tastes. When used correctly, sequins can transform an ordinary event into a dazzling experience.