[kunai]

I never really used iMessage. It never made any sense when I had been using AIM since 2002; why not continue?

I like the ability to contact phone numbers rather than user IDs, but apart from that, one AIM account on all devices seems to be a better proposition, at least in my experience.

And for the record, yes, I still use AIM.

[randomdata]

On iPhones, you don't explicitly use iMessage, it just switches to iMessage automatically when sending an SMS message to a recipient also uses iMessage. That is the primary reason to use it, though it is handy to be able to send messages on the network via other Apple devices as well.

[aerique]

I had to turn iMessage off on my iPhone since it was extremely flaky for me and an acquaintance: messages would not be delivered or much later. WhatsApp is better but SMS has been the most reliable so far.

This is using T-Mobile in the Netherlands.

[mikeash]

iMessage is great for communicating with less-technical people who I'm never going to convince to use something like AIM. And once I'm using it for them, might as well use it for everybody, at least within the Apple universe.