Jay wrote on 05/12/12 at 05:35:29:
I think the DW lines are fun to try but not for too serious play.
For sure they are - I like Ivan Sokolov writing in his book "The Ruy Lopez Revisited" that if you play a line which may be slightly dubious (but certainly has a bite and therefore gives you excellent practical chances) and you invest 50 hours investigating that line, you can be sure that you have an advantage. On such line in his book is 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 f5!?
"Fun to try" is read by me: "I don't want to spend time on it" - but exactly that is what you need to do in those offbeat systems - become an expert!
From my personal chess practise:
I won more games with somewhat strange, "dangerous" lines than with main lines
I lost more games against somewhat strange, "dangerous" lines than against main lines
In bose cases solving problems over the board is the key. It even worked for me against strong opponents - in fact my first win against a FM was back in the early 1990s with the Morra Gambit, when I was only rated around 1.700. The mix was perfect: A "dubious" line, which I prepared against the Sicilian for some time and a massive underestimation of my strength (due to my elo at that time) - the end of the story was a highly embarrassed FM who told me that the Morra is not correct. Well - this may sound familiar to all the guys out there who play "dangerous sidelines" - most of their opponents will tell you something similar after the game or even come back one day and show you the "refutation".