[naitbit]

> Modern browsers allow a user to type (in lowercase) text to find in a select element while focused and will scroll to an exact match inside of it.

Additionally they always highlight item that begins with typed letter. Because of that in default combobox i can type only "po" to get Poland, whereas search after typing "po" highlights French Polynesia. I think that difference is worth noting because it may searchbox more or less useful depending on data.