About time to market: From my experience (and Reinertsen [1]) time to market is not lost during programming but during the decision phase. Optimize your decision speed (reduce meetings, don't postpone decisions, have a clear decider, know what to decide and what not, ...), not your technology stack if you want to beat others to market.
I did have an offer for some years: Anyone beating a Java (the COBOL of the internet world) stack 5x to market, I pay him $1000. No one did take it yet.
One of my slide deck on the topic:
http://www.slideshare.net/Stephan.Schmidt/what-everyone-shou...
[1] "Developing Products in Half the Time: New Rules, New Tools" Preston G. Smith, Donald G. Reinertsen