I read sheetmusic and like to see it with the tab since it lets me know a bit more clearly the weight of the notes — whether it’s a quarter note or half note or part of a triplet etc. It can also be helpful if I want to try out something on a different instrument. There are some tab programs that display the note values as part of the tab and if that is there I’m happy to do without the traditional sheetmusic part.
However I definitely always want the tab since that tells me what string is meant to be played for that note since a single musical note can often be played on several strings. That information is an essential part of an ukulele arrangement.
So, if the tab displays note value, we can live without the sheetmusic part, but the sheetmusic without the tab isn’t too useful.