But which tacks are quicker?

You are losing a bit of ground to windward with the kinked exit, but you're probably also accelerating quicker.

Remember it may not be a case of steering to leeward either, it could be a greater loss of speed through the tack that means your leeway angle increases. In which case it is probably a slow tack.

Measure time between identically spaced ladder rungs (one to leeward before tack, one to windward after tack) to determine which tack is better.

To confuse it even more, there could also be tidal influences. Ignore unless you know there is a significant affect. You could also be jamming the mainsheet back on too quickly.