Lumineers CAN work when you are doing a LOT of them (for example, at least eight to ten teeth). In that situation the shape and size can be generally matched. I would do Lumineers for someone who is not too picky about the final result. There WILL be variations in the colorations, because the thicknesses of the Lumineers will vary.
Another consideration is that the bite has to be matched extremely well for the Lumineers (or any porcelain veneers) to hold up well.
In general, the main advertised advantage for Lumineers is that the teeth are not prepared, drilled or shaved down. There are other systems (other brands) that can allow that same non-invasive approach, but done in a way to give more personalization and better color matching. I choose this approach MOST of the time.
Any veneers can be a big improvement, but beautifully crafted, thoughtfully color matched, and meticulously bonded, and precision matching of the bite will provide you with MNAY years of beauty and a magnificent smile, without regrets! (and the envy of your friends).