A DM works if it is reliable  and goes in smoothly and positively every time. I've been disappointed  with some of the Remington products. ( I sold them for 6  months about  5 years ago)
The thing is  can you do it under stress every time - like, you're driving  around the bend, and ther's the moose of your dreams  walking towards the bush.  Try  practicing inserting the loaded mag  AND reefing  one in the chamber from the inserted mag, then retry with an empty mag in the gun and  tossing a round in the  chamber like you can with a regular non DM magazine. If you can, try that exercise, fire at a target, then rechamber a round, either using the full mag  or empty mag and some other ammo source. Try to introduce a bit of stress in the situation, then see  what your  time and hits  are.
For me , hunting, no question, travelling with an open action, tossing a round  in ,firing is a lot faster. your mileage may vary....