I tried this at some points where I often have to allocate dynamic memory though I knew an upper bound (no static size, though). Got some nice (and easy) extra performance, thank you (and the others who replied to my comment) very much for the hint!
Maybe in a logarithmic plot this would look differently, but it seems to me that std::vector performs quite well in particular for few elements. So why would I bother with smallVector if simple std::vector is on par in their (supposed) prime discipline?
While this has indeed very scary implications, one should be aware that if it's thinkable, eventually it will be thought (I'm paraphrasing here).