The biggest practical difference I think is that the pin locks are a bit wider which can make a big difference sometimes on how many you can fit in a particular fridge.
An advantage to pin locks is that you cannot put the wrong disconnect on the wrong post (I've only done it once on a ball lock but some people are more accident prone and they are a pain to get off if you do it).
Generally ball locks are more available, but this is highly regional.
So my advice is this: Be aware of the size difference. Buy what seems more available and is cheaper in your neck of the woods and its really not that bad to use a mix if you have flare fittings on everything.
The biggest practical difference I think is that the pin locks are a bit wider which can make a big difference sometimes on how many you can fit in a particular fridge.
And to add to this, conversly, the Ball locks are taller which may or may not impact whether or not they'll fit that way too.
Pin lock or Ball lock?
Linear Mode
