If I was a new diver, having done my homework, I would buy a Peregrine
There has been a poll about buying a rec computer. After ease of use, good UI, and readability, the most important variable was the deco algorithm
Single most important factor in choosing a recreational dive computer You can make a liberal computer more conservative, but you cannot make conservative computer more liberal. Other than perhaps DSAT, I would opt for Buhlmann. Three of the 4 computers you list run this algorithm.
If you are on a budget, you can't beat the D6 Excursion. One would like to hope the lack of apps and a NDL planner will be taken care of soon. It handles deco in an unusual way, of no concern to rec divers. The Mission One currently costs the same as the Peregrine, it was previously available at a discount. Some of the features of the M1 appear desirable, however, Shearwater has the best service record in the industry. Some of the features on the SW, such as SurfGF, have proved incredibly valuable to me.
Best of luck in your purchase