Why do you want new fins? What are your current ones doing or not doing that they need replacing?
I've owned as many as 10 sets of fins at one time from different manufacturers and am now down to 4. Two sets of HOG tech fins in size L and XXL (for use with a drysuit), my original Aqualung blades from 2004, and a set of MAKO free diving fins. All of the other ones I've sold or given away.
Given the two you note, I pick neither for a couple of reasons:
1 No spring straps on the Atomic
2 The MARES just looks gimmicky and they use a lot of words to say that the fin will do what all fins will do if you know how to kick properly.
3 Over priced
I have had fins for open ocean diving (Hollis F-1s) that worked well but were big and heavy. They helped to go fast but I decided a long time ago that speed is not a big deal.
The HOG tech fins work well in confined spaces and I can move as fast with those as the Hollis.
I still have my original blades because they are light compared to larger fins but pretty much neutral in the water and I have hung on to them because they were my first pair and are damn near indestructible.
The MAKO I have because I took up free diving to a very small degree and I like how a small flick can get me going while I'm snorkeling and don't want the heavier fins. They are super light and don't require boots. Just neoprene socks.
If you have decided to take up an area of diving that may call for a specific type of fin, what's wrong about the ones you have for that?