You always need to check the actual curves of the exact component (if available). Rule of thumb: a smaller ("too-good-to-be-true") device usually has worse DC bias, ageing and temperature characteristics, all at once. So simply avoiding Y5V might not be enough. A lot of homework to do when designing.
This. Exactly this. I just handled populating the BOM for a new product and I spent more time on cap selection than any other type of component. There is NO consistency across manufacturers... sometimes Samsung has the better curves in its spec sheet, other times Taido Yuden, sometimes Murata, etc. Yaego doesn't even publish some important curves for many of their caps, so their products don't get approved for our projects.
There are no ideal components, but caps are especially weird beasts. We try hard to never run them beyond 33% of their rated voltage (5V bypass caps are always at least 15V, and often 25V) and then we consult the curves to see how they are derated with DC bias. We recently dropped 4.7uF/25V caps in one 12V application because we found that a 10uF/25V we were already using had MORE than 4.7uF effective capacitance at 12V. (Imagine what the 4.7uF looked like at 12V.) Yes, it violates our "33%" rule but if we're making an informed decision, operating within specs, and still below 50% rated voltage, why stock both parts? With the increased volume of the single part the price was basically a wash. The package sizes were the same too.