Apparently haha.
haha
that was funny!
I love my brakes for MUni, yet will not use any for cokering, as roads don’t get as steep as trails do! I’ve gone down HUGE hills with and without brakes, and I love my brakes because of it. It takes a while to get really good with them and adjust them the way you want, but once they’re set it would be hard to part with them. I’d say I do 2x the distance with brakes than I do without, but my trail has hills EVERYWHERE, it looks a bit like this: ////// 
you understand, and for that i am thankful
I reckon brakes sorta defeat one of unicycles purposes (simplicity) but I can see how they could be useful.
I dont use a brake. A lot of my rides are miles of uphill, and then miles of downhill, or some really steep muni trails, for both muni or coker. I just dont use brakes, and dont feel the need to.
Im pretty fit, and long descents or super steep parts dont really effect my legs. Sure I can feel them being used more than usual, and if I had a brake, I could give my legs a little rest, but id rather not do that.
As long as you don’t add in a chain and derailleur, the complexity isn’t bad. When I was on MUT, nobody had brake issues that needed maintaining, and the bike support were fixing their gear every evening. So as long as the coker remains zero maintenance I’m okay with added complexity.
On the subject of brakes though - I didn’t think I needed one until that tour. Where I live it is very bumpy - lots of 50-100m ascents within say half a kilometer. For going down those, it’s usually not a problem, although there are a few that it is nice to have a brake on. Some places have kilometers of 5-9% grade. After about a kilometer of riding slow on the downhill and burning all that energy you wish you had a brake 
I have a magura fitted to my coker, and while I tend to use pedal resistance for most hills, since I’ve got to be a bit more careful when using the brake, there are a few hills where I can’t physically put enough down force into the pedals to stop the coker (this includes both hands pulling up on the saddle as hard as I can manage in addition to body weight). I’ve broken main cap bolts (on the bottom of my frame) this way. Every time I go down something this steep and stick the brake on, I feel so glad to have it 
I’ve put a brake (just a cheap BMX caliper) on my coker, but only for one hill on my usual commuting route. It’s something like 1:6 for half a mile, with a bit of 1:5 thrown in, and although I can ride it without the brake on 150s (and have to if it’s wet - steel rim) it’s much less scary with a bit of drag. That’s the only place I regularly use the brake, although I have used it on similarly steep hills in the middle of long rides when my legs are flagging a bit.
I don’t have a brake on my 26" muni (also on 150s) and don’t see a need for it (that hill I mentioned above isn’t bad on the 26), but then I don’t tend to ride super-steep stuff anyway.
Rob
EDIT: for the “hills as percentages” fans, 1:6 is about 17%, 1:5 is 20%.
I’m ashamed to say I’ve got a brake on both my muni and my commuter now.
The commuter I don’t usually use the brake round near here, as there aren’t any steep long road hills, but it’s nice to have on big long descents, or things that are too steep. It’s got 125mm cranks and 45" gear, so does tend to be a bit fiddly on downhills. I certainly used it on some descents in New Zealand including one with 800m of descent in 5km, which had hardly anything less steep than 1:5 for what seemed like ages, and a few very steep bits that I couldn’t even ride in 29" gear, I know the guy I was with had trouble on a 24" muni.
The muni, I never had a brake until recently, cos brakes are a bit dirty really, but I guess I did need it for our Alps trip, where we were doing over 2000m (6500 feet) of descending every day for 5 days. I’ve done one day rides with that much descent brakeless, but getting up the day after doing 3000m of descent and getting out riding again is hard even with a brake.
I think on the muni, the brake affects your perception of what is steep, I know a couple of times in the Alps I came off on steep sections and discovered they were too steep to walk. That’s okay for short bits with a run out, but if you’ve got a sustained ride down a mountain that is super steep, there’s a point at which it becomes impossible brakeless.
Joe
Because I don’t want to kill (damage) my knees. I have other unicycles with no frills on them, but I don’t try to ride them 100km in a day. No Schlumpf for you! 
If your knees don’t have a problem, you’re all right. Just remember to listen to your body throughout the years. I want to still be able to ride when I’m 100. My friend Brett Bymaster can barely ride at all anymore due to too many knee injuries.