Is anyone else seeing a lot of their blue iMessages reverting to regular text messaging?

This happens when the recipient cannot receive the iMessage within a certain time, so Apple/iCloud is assuming that no data connection is available and retrying by SMS instead.

My immediate thought is that iMessage is a new service and over time this will improve... but what if it's something more sinister? What if it's actually saying quite a lot about the UK mobile networks?

When people are on WiFi it generally seems to work fine. But when they're off on cellular it gets a bit... hit and miss. Any thoughts?

This isn't really a moan about iMessage; I think it's fantastic! But something's not quite perfect.