In my experience, SMS is still many times worse. Long messages arrive out of order and parts sometimes do not arrive at all. I've had messages to friends on AT&T delivered 36 hours late, causing confusion.

iMessage, on the other hand, has mandatory delivery confirmation (so you can at least know if a message is going to be problematic) and optional read receipts.

To the people saying this is not a problem, it is. In particular, iMessage seems to often get confused when trying to send a picture. The progress bar will get to half or even mostly full, and then just pause ...forever.

It's not a connection issue. On several occasions after running into this iMessage issue, I have emailed the picture full-res without problems.

That said, I don't think iMessage is terrible. I love it when it works as expected.

Odd, in the UK I get almost 100% success - plus you get the handy delivered (and optionally read) notifications.

Never had such problems. I use it both from desktop and my phone, works just fine.

Never had this problem, and with one exception everyone I text with has an iPhone.

I've never experienced this. Sounds like a general network issue, not an iMessage issue. Junk network equipment at home? Badly oversubscribed LTE/3g in your area?