lithium or wheezy or jessie



I need to choose a branch to base my project on.
Tried the lithium iso and it is still based on Debian squeeze. I would like to
stay away from squeeze if at all possible.

Tried to build an iso using jessie-transit branch and it failed to build
because package dependency mismatch between libboost-iostream1.54
and aptitude 0.6.10.

Can someone shed some light on the nature of the experimental branches?
E.g. are they close to become a future product release? Do they go through
rigorous testings? Do they have daily builds with build logs?

Also what happen to wheezy-transit? Is it stable?

Thanks for help.