Anyone who's into cycling...

makes your pedal cycle smoother too, right?

It can, if you work on rotating your feet rather then mashing. But you can still mash with a fixed.

It builds really good spinning techniqueā€¦But that would only matter to someone if they are also a roadie haha

spinning is really important in mt. bike climbing, and touring as well as road biking, in other words its really helpful always if you are on a bike.

I road a fixie for a while , I didnā€™t like it . I can never under stand why so many people ride them in the city streets sooooooo dangerous . I knew a lot of people who got mangled on one . and one who even died. Iā€™ve been in some tough spots in traffic on a bike , and a skid or a hop just isnā€™t gonna stop you in time .

thatā€™s why if you ride them, ride with at the very least a front brake. Preferably both brakes.
And itā€™s true that theyā€™re excellent for rounding out your stroke, thatā€™s the main reason I have one. A round stroke is essential for good riding of any type, be it road or mountain.