Do you think that they should be used?  I have three challenges left on the 3DS version with all three hammers remaining and five challenges left on the Wii U version with all five hammers remaining.  Each of the challenges are hammerable.  Should I just hammer all of the challenges out and gloat about how awesome I am or should I complete all of the challenges and gloat about how awesome I am later on?

Seriously though, do you feel as though it is cheating if you use one?  Have you ever used one and on what challenges?  

Once I tried to use one on Boss Battles on Intense in Brawl.  Not only did I feel shame in doing it, but I was denied by unbreakable glass...

They existed in Brawl? o.o Hmm I guess I only ever knew about the Melee ones.
It feels like cheating imo but I'm too lazy to do some of the challenges so I dont care too much

I use the hammers on the most difficult ones (that can be broken). I don't regret it one bit.

A few challenges are just way too time consuming, which is why hammers save me alot of trouble.

Are there any challenges that you have used them on in Smash 4?

I used the hammers for the Street Pass stuff mostly just because I don't want to deal with that.

They exist in the game for a reason.

I'll try to do as many challenges on my own, then use my hammers.

Neh, some of the challenges are pretty hard so I m glad they r a thing

Not for now but I have yet to reach the hardest ones! I am totally going to use them there.

You know that you could complete those in practic, right?  

All of them except 10 hits or whatever it was.