I've recently finished the schematics for my ~900 component device. I have primarily used 0805 capacitors as a starting point, as I'll be assembling the board manually (most likely using a toaster oven/stove to reflow at this point) and want a size which is relatively manageable. I've untangled the ratsnest and placed the components in their rough position, and I think 0805 is going to be too big. Note: I have larger electrolytics which aren't my concern, I'm more interested in the ceramic decoupling/bypass capacitors.
Given that I'll be reflowing, I think I should be fine to use 0402. Some of the capacitors require a 50V rating, so I'll use the smallest size I can for the given type (e.g. X7R, X5R, etc.).
My question: other than voltage rating and cost, are there any performance, capacitance, inductance, etc. considerations when choosing between two SMD/SMT capacitors of the same specification in two different sizes (e.g. 0402 or 0603 vs. 0805)? I came across a post on StackExchange where a user had posted part of their layout, and multiple commenters stated that the use of 0805 was sub-optimal (for the given purpose I assume), and that they should use 0402 instead, maybe 0603 at a push.