Pre-designed tips have actually been a godsend for me, as I'm no artist. I could never come up with the nail art I've seen some of you do. One of my clients LOVES solid black tips and will have nothing else. But yeah, it isn't feasible to do a full removal then replace with new tips every 3 weeks.
So to combat that issue, I place the tips high enough so that she usually only needs them replaced every 2nd fill (but not so high it looks unnatural). I suggested once we try a black gel to "paint" her tip (and then freshen/re-do it each fill) to see what she thought. It looked good however, she still prefers the "sharpness" of the solid black tip.
So now I just replace them every 2nd fill and she's happy. I tried pink ones on myself and enjoyed them and whenever I get a color or pattern, there's a fair bit of curiosity and excitement at the salon lol.
I charge more for these because they cost me more: $50 for a new set (as opposed to $45 for a "regular" French gel mani).
The only other issue I have found with these is that they sometimes don't "fit" as well as regular prosthetic, but that could be just the brand I'm using.
I'm actually off today to get some new colors and patterns.
If you'd like to see them, I've made an album of my work.