To answer the OP, it depends on how much brightness or runtime you would expect. This will not be useful to you, but it is the best I can say with the info on the requirements you desire. Please give us more info on what you want or need... Being the best depends on the user... (ramble mode: on)...
I think that the best Mag mod depends on the owner, or the creator. We design around characteristics we desire. I love the tint and the performance of my quad TFFC 0200 K2 behind basic IMS 20mm reflectors and powered by a Maxflex, and contained in a 2C mag with AW C cells. The beam is beutiful, and the modes are convenient and customizable. However, I am using cheap plastic reflectors and LEDs that perform well, but are not the most efficient (compared to what is available at time of post) when driven at full power -900lm from 16W input.
That is my opinion, and my custom design. I would love to use newer, and more efficient emitters, but for the cost, this was semi-easy to afford (I wish I could use nice McR reflectors), and the beam is very pretty.
If could be a better light (in my eyes), then I would buy the parts when I can afford them, then build it. Seven neutral white Rebel 0100 emitters driven at 1.2A from the Maxflex and McGizmo's wonderful McR-12R or McR-18 reflectors would be great. So would a Cree XP-G behind Mag's new stock reflector driven at over 1A. I would love to have a fin cut Mag that is cut down with flutes and a chrome or HA-III coating with a custom heatsink and high-end LED(s). I would also wish I could afford a lathe.
So, my post is part rambling, and part sampling of what you could do with a Mag. So, when deciding on what Mag mod to build, be unique (or not) and make a Mag with features and properties you like, need, ...or can afford. Once you make a decision, please ask us for help on how to build it. We are here for you.
-Tony