I have used both while grading papers at my kitchen table, and the winner was always the one I could keep in place without drooling into my tea.
So what is the honest answer?
Strips are cheaper and easier, trays cover better, but fit matters more than the label.
If strips slide, dry your teeth first, press from the gumline down, then fold the excess behind the tooth. If trays ooze gel, you used too much. A rice grain sized line per tooth area is plenty.
The part people usually miss
Choose strips for quick surface stains and trays when you want more even contact around rotated teeth. Skip both if your gums are already sore that week.
My rule is boring and useful: change one thing, watch what happens, and stop if your mouth gets irritated. Teeth respond better to steady habits than to panic routines before weddings, photos, or dentist appointments.
How I would handle it this week
- Take a baseline photo in bathroom lighting you can repeat.
- Keep brushing gentle at the gumline, soft bristles only.
- Do not stack three new products at once, because then you cannot tell what helped or hurt.
Related reading: this guide and this review or article both go deeper on the practical side.