The advantage was we could see things working.
This disadvantage was that one of our major subsystems only got ported as a skeleton.
I have spent the last week and a half putting meat onto that skeleton, which involved a major rewrite of some fifteen year old code of mine.
Happily, I am better at design and coding than I was fifteen years ago. But the rewriting is killing me.
There is a light at the end of the tunnel. I am fairly sure it is not a train. :)