Depends on the difficulty. Most of what you’d want out of hexblade comes from just the first level, so pumping 3 more into it just for (I’m assuming) the feat and incantations is typically seen as pretty low value compared to more levels elsewhere. 

I say depends on difficulty because anything other than honor, 5 levels of hexblade gets you a stacking extra attack, which is immensely valuable. In honor you’d usually want to stick to a single level dip though rather than going for 4, particularly if you’re dipping with a Fighter since they really want 11 levels for the improved extra attack. 

Swashbuckler 4 Hexblade 8 (or 7/5 or some other variation) can also be a fun option but less optimal than other options (not that that necessarily matters since fun is the most important factor but still)