Since F# 4.0 it has been possible to do C# LINQ style automatic convertion of function arguments into quoted expression trees. In the case of FSharp.AWS.DynamoDB this means that an update expression can be written as follows:
table.UpdateItem(key, fun e -> { e with Value = e.Value + 1L })
without having to quote the lambda argument. It's a nice enhancement without introducing any breaking changes.