I’ve seen them get a fair amount of use. Direct node connections are often faster, but not as capable, so it depends on the use.
And they are faster than expressions.
Go with SDK’s, expressions are considered a no no - the evaluation graph/profiler considers them thread unsafe and relegates them to global serial - meaning there must get evaluated prior to any other node.
You could also use a RBF solver.
There is a free one from Brave Rabbit.
http://www.braverabbit.com/weightdriver/
Or the build in one.