(committer on Antidote, author of Lasp, both SyncFree projects)
Antidote is designed for DC deployments, in the hundreds of clusters. It provides causal consistency and transactions.
Lasp is designed for high-churn, edge deployments (with CRDTs) and provides eventual consistency: it's designed for 1,000+ nodes.
They share a bit of code, and you might want to evaluate both to determine which is a better use case: Lasp might be a better fit for the IoT application, because it was designed for that.
Here's a HN post on Lasp's scalability:
https://news.ycombinator.com/item?id=15444156
Here's a HN post on Lasp: