Small detail, but a cypress is a tree. A CYPRES (Cybernetic Parachute Release System) is the Godfather of modern AAD's.
Also CYPRES warranty is "lifetime" provided you send your unit in for 5/10 year revision (during which the battery is changed). If I had a new CYPRES, I would send it in for the recommended revisions.
I might be slightly biased because I had my life saved by a CYPRES (check my profile picture), but :
Things I prefer with the Cypres : fire/non fire parameters, cutter blade, customer service, changeable filter, loops and discs and temp pins and related rigger goodies
Things I dislike with the Cypres : the purple stickers fade away quickly
Things I prefer with the Vigil : the thickness of the cutter cable, the colours (blue and orange is awesome), the aluminium case in which the device comes, the orange pull up cord
Things I dislike with both : too many possibilities to get stuff wrong with the offset /mode/alt changes etc.... I preferred the simplicity of an original Cypres. Change the offset, if offset is too important switch off, if not comfy with an AAD OFF, don't jump. Simple as that. And even that, some people managed to screw up.
I have 0 experience with the MaRS so I can't judge.
Cost should not be a decisive factor when purchasing an AAD.
Edited to add : Also for the video of the cutter going through wire, it is pretty easy (in my opinion ) to cut "hard/tense" material. So I asked them to show the same with a Cypres loop without tension, as soft stuff is sometimes harder to cut, and it worked like a charm. Eventhough you can clearly see the difference between a loop cut with or without tension