Short version:
I got one of these on Saturday. $29 from Dive Gear Express:
DGX Ultra View Frameless Mask
I used it for 2 dives in the local quarry yesterday and it was awesome. I'm going to order another now, so I have a backup.
Longer:
I've been diving Seavision 2100 masks for the last 3+ years. I like the SV masks for the magenta lens in blue water, and for the built-in gauge reader lenses. I originally bought mine after trying a buddy's when we were diving in Hawaii. He prompted me to try his so I could see how nice the magenta lens was for color correction. He was right and the color correction is great. But, my previous mask, an Atomic Frameless, always leaked a bit. During my first dive with the SV, I didn't have to clear the mask a single time. That is what really hooked me.
In the time since then, I found that they did still leak some. And, for some reason, it seems like it has gotten worse over time. I don't know if that's because my face has changed or what. Anyway...
I had been eyeing the DGX mask for a while. It's so inexpensive, I really wanted to try one just to see if it leaked less. I finally broke down and ordered one last week.
The first thing I noticed is how much bigger the field of view is with the DGX mask, compared to the SV 2100. The SV mask frame definitely takes up some space in my field of view in every direction. The DGX mask gives so much more, I was VERY surprised. With the mask on, on the surface, looking straight ahead, I can't see any of the frame on the top and bottom. And I can only see a little bit at the very edges of the sides of my peripheral vision.
The mask FEELS a lot bigger on my face - as in wider and taller. But, it also seems to be significantly lower volume. It feels like it sits noticeably closer to my face. I figured that might mean it would be easier to clear. I still don't know about that because, after 2 dives, I realized I never had to clear my mask the whole time.
Also, the SV 2100 has part of the frame, on each side, that sticks backwards and that is what the strap connects to. So the SV mask strap doesn't connect to the mask skirt at all. But, it means that the mask cannot fold totally flat. As a result, I had one of my SV masks in my drysuit pocket for a dive (as a backup) and ended up breaking it. I guess I leaned against something too hard. Not difficult, I guess, when handling double steels on a pitching boat. But, in contrast, the DGX mask strap buckles are attached to the mask skirt itself, so it can be folded totally flat. Perfect for a drysuit pocket. I have to throw a "pro" to the SV mask, though. First, I superglued it to fix the broken strap flange and it has been fine. But, I emailed SV and they said if superglue didn't fix it I could send it to them and they would transplant the lenses into a new frame for $45. I feel like that is good service that is worth noting. Their lenses are not cheap!
And, the SV mask strap itself is narrower than "standard". I had ordered a DGX slap strap a while back and the side straps were too [EDIT: Used to say "narrow"] wide to fit through the SV mask buckles, so I had to stick with the stock mask strap. With the DGX mask, the buckles are exactly the right size to use their slap strap - so another bonus. The stock DGX mask strap is nice, heavy-feeling silicone. But, I took it off first thing and put on the slap strap that I had previously purchased. The DGX slap strap is $10, but you can order it custom embroidered with your name or whatever for $22.
The SV magenta lens is nice for the color correction, but I am going to live without it, going forward. The pros of the DGX mask really outweigh the color correction, for me.
The DGX mask is not available with gauge reader lenses, but that may no longer be an issue for me. I'm generally only diving these days with computers like my Perdix, which I found yesterday I can read just fine without reader lenses. However, if I do decide I want gauge readers, I will put in some Hydro-Tac lenses. They cost $15 and I have used them before in my original Atomic mask and they work just fine. You just have to put them in and let them dry for 24 - 48 hours before you get them wet.
The DGX mask even came in one of their triple layer mesh bags. I was not expecting that and I was not expecting the bag to be anything worth keeping. I was wrong about that! I feels surprisingly thick. Obviously, it's no protection against something that would break the mask frame. But, for protection against anything less than that, it seems like it will be good. My new mask is in that mesh bag, in my dive bag with my fins, BCD, etc., right now. I'll probably continue to use that, rather than worry about trying to keep it in a hard case.
Last, I note that, just based on APPEARANCE, this $29 mask from DGX LOOKS like the identical mask to the Dive Rite ES155 mask ($69) and the new Sub Gravity Vadose mask ($89). Of course, I have no way to know for sure. And I say that based solely on looking at online pictures of the DR and SG masks. They could all have different glass in them that makes the others "better" than the DGX mask. No idea. I just know the glass in the $29 mask seems perfectly good enough for me.