Signal app message synchronization reliable?

I've been thinking of switching to Signal app for all of my communications going forward. I read that message synchronization isn't reliable where messages may appear on my phone, but not on my PC. iMessage and I think even Skype had that problem during its early days. The problem was largely resolved once messages were stored in the cloud. I would love to continue to use iMessage, but not everyone have an iPhone. Any Signal users able to comment on this?