Its cheap, looks good, customizable;

Doesnt spin well. The pen is too back heavy, the hgg tip at the front doesnt add enough weight at all. I also made a signo tipped one, that on the other hand spins pretty well even though it becomes a quite heavy and "dense" mod for its size. Imo.

Construction is simple but quite finicky: both the tip must be fitted properly or they will come loose now and then. Personally i have figured out a good way to fit the tips, but not an elegant one for the cap. The ink rattles when hitting the front of the pen. I fixed that with a couple of turns of teflon tape.

I like spinning the signo tipped one. The og, not really. Every know and then i pick it up for a challenge but not very often.

RAMBLE AHEAD

Imo its very popular because its a "factory produced" style of mod. Like, most people spin dc but at some point they want to try sc for the sake of it. You can come up with something and your own (but construction and balance is quite more complicated than taking a marker, removing the ink, double capping it, and slapping a pair of tips and grips) or make a well known mod which most are G3 variations that take an unreasonable amount of pens to build (and price!) that not many people want to commit to. Then they stumble upon the mx. Its simple to build. No barrel cutting, grip doodling or else. Its not built like a violin like some overly engineered g3. You choose the color of your rsvp. You choose the color of your hgg. You slap them together, and look for an insert on google and skideet skidoot you have yourself a sc mod which is simple, its built with only two damn pens, looks cool but best of all its special like the special flower you are because of the infinite customizability. You spin it a couple of times, send the hgg flying a couple of times, and you stick it in your pen case because its fly af. And keep spinning your waterfall.