Spearing masks

Far the most important thing about the mask is its fit to the face.
The best mask in the world is not good if it is leaking or if it is not comfortable.
Good test during the purchase in the shop is to put it on the face without putting the strap on your head and slightly press it against the face. The mask should stay there. If it does not, try another one.

We all have slightly different bone structure of the face, hence not everyone likes the same mask.

Personally, I use minima, aquasphere and this one:
MAKO Spearguns - Mirror Tech Freedive Mask

Aquasphere for (non-spearing) deep dives due to softness of the mask, minima for deep-ish spearfishing and mako when conditions are clear and if the light is ok.

I have used the OMER Alien, Sporasub Mystic and Aquasphere Sphera. The Alien is a good mask and was the first I bought after starting to get thoroughly into spearing a few years back. It has a comfortable skirt and is rather low volume. I bought the Mystic to replace the Alien a while ago because of the stated lower volume and better field of view. I can’t really say I feel much of a difference in terms of field of view (have never properly tested), but I do notice I don’t need to equalize the mask as often as with the Alien. The Mystic skirt is much softer though, making it feel even more comfortable. I recently bought the Sphera because it was said to have an excellent field of view and low volume, but I was thoroughly disappointed. The larger field of view comes at a compromise; the rounded lens edges let light in, but it is impossible to see clearly in that area, so it’s only distracting and uncomfortable as the mask becomes brighter inside without giving you a larger focussed field of view. This is especially bad in high viz/bright situations. In addition, the skirt on the Sphera is stiff compared to both the Alien and The Mystic, and the frame is a bad fit for my face, effectively rubbing the bridge of my nose. I also had to equalize the Sphera far more often than both the Alien and Mystic masks, so I stopped using it completely.
My favourite mask is now the Mystic, and I use it for pretty much all my diving.