Whenever there's an iPhone update, do you update it?

I don't, I still have the old (iPhone) emoji keyboard and although I'm tempted to install IOS 8.4 I'm a little hesitant b/c 1)I don't know if it's worth it. 2) My storage is almost full.
I have an iPhone 5c.
What about you? Do you install new IOS's? Will you be installing iOS 8.4 if you haven't already?

Don't have an iPhone, but if Samsung did it I'd update.

I have a iPhone 5C also, just been chilling on IOS7 since September 2014. I have no space to update. I did want iOS 8 to get the new emojis when they came out. But people told me ios8 in general is rubbish and the main reason I want to update is to get new music as I can't download music illegally due to me not updating my phone so that's the only drawback. But I'm due an upgrade in 2 months time so I see no point in updating personally.
Sorry I kind of waffled on about myself. To answer your question I wouldn't waste my time updating if I was you due to lack of storage space and no I won't be installing iOS 8.4

Done it but it uses over 5GB so not really practical on an 8 or 16 GB phone

I have the iPhone 4s and I'm still using the OS 6.0.1
I never update and don't see the reason to