To find out what a radian is you take the length of the radius of a circle. Then from the point where the radius hits the edge of a circle, measure that the same distance along the circumstances, then back to the center of the circle, making a triangle with three equal lines each of which is the length of the radius.
Now you divide that triangle by 1000 and that gives you mil-radians
Mil adjusting scopes come in 1/10 mil clicks.
With the MOA scope, each click moves the point of impact 1 inch (to be more precise, 1.047 inches) 1/4 click will be 1/4 or .25 inches.
A .1 mil click will move the impact 1/10 of a mil at 100 yards.
So if 1 mil = 3.348 inches, then .1 mil will move the impact .3348 inches.
Since its simpler to say and remember 1 MOA is an inch, then 1/4 MOA is 1/4 inch, THEN we can also make it easy to say .1 mil is 1/3 inch at 100 yards (.3348 is pretty close to .333 1/3)
just to to be clear MOA is not imperial and Mils are not metric.
Now on to the other part of the question. Is the math easier. Yes and no. If you use SMOA AKA shooters MOA then the math is really just using 1 inch at 100 yards and then using 1/4th or 1/8th to divide. Yes MOA is generally speaking more precise than MRAD. One MRAD is 1/3 of an inch at 100 yards. The cost of using MOA comes at losing turns on the turret and reticle. 1/8 MOA will cost you a lot of vertical dope. The MRAD scope is easier to use because it's a base 10. That means the numbers are easier to find. If I tell you to dope your turret 3.6 MRAD then that is an easy find. Plus if your scope has 48 50 or 60 clicks per full turn you know that each full turn will be 4.8, 5 or 6 MRAD easy. The other factor is being able to turn the turret to match the reticle. This is a nice feature to have. The last factor is the reticle it's self. I happen to know that the falcon ffp has a pretty thick reticle. It is so thick that it won't be super precise at 50 yards at full magnification.
I use MRAD scopes in yards because as an American I think in yards. I can easily see a football field in front of me. I would go with the mil/mil. Always get matching reticle and turret whenever you can. If you are going for a target shooter choose a different scope. I think 2nd focal are better for this application because the reticle is thinner. This will make a difference when you are trying to 10x as many times as possible. For hunting the MRAD is more user friendly and quicker. If you are hunting squirrels doping drop under time is the difference between success and failure. MRAD is better because you will use less turns and the numbers are easier to find. Imagine you see a squirrel you ballistic calculator says 23.2 MOA you look on your turret and it says 1 through 14. You start counting one full turn is 14 MOA then 2/3 turn is 24 MOA then back one two three clicks damn where was it oh yeah two clicks above 9 and two below 10 MOA on my second turn. Damn the squirrel is gone. Or it your calculator says 10.6 MRAD 10.5 will be clearly marked on the turret. Bam one click above 10.5 equals a very unhappy squirrel.