Both in house. Both 300m divers. Both awesome.
1 jap 1 swiss. 1 cosc 1 unregulated GS movement.
Some say the mm300 is superior by the $, some say its just plain better.
Some think the SubC is living on the Rolex mystique, some say it set the bar for all that followed.
The face:

u can see the uneven lume application on the mm300


SubC has the piano black dial. MM300 more matte with some brown in it.
The white gold indices are a nice little touch, while the gilt gold has me swooning.
Both are 4 liners.

the rehaut and raised chapter ring plus the domed crystal makes it a deep dial.

some find the rolex engraved rehaut an overkill, I don't mind it.
I like the mercedes hands.

the fat hands of the mm300 are pretty kick ass though.


lollypop vs traffic lights seconds hand


The case:
1 monocoque, 1 with the tightest caseback ever.

1's all angles and sharp machined edges, 1 is all curvy and flowy.



Both 40mm. 1 super top heavy, 1 fits like a glove.


1 with some manly lugs, 1 with the 4 o'clock crown. I am glad there's no HEV.
The misc:
ceramic bezel is a winner.

recessed lume pip is kinda cool though

the rolex bracelet is 2nd to none...i haven't even sized the seiko bracelet yet

unsigned crown is a bit sad

good thing the caseback is kinda fun

still very good lookin

no slouch either
The conclusion:The mm300 is superb FOR the $, but the SubC is still miles ahead as far as fit finish prestige etc etc.
The argument tends to be that its not 6k better...I would say so what..better is better. There is a place for both in a collection.



Lume shots of course:cool blue


nuclear

