I have been using tinc for quite a long time and it feels pretty stable, but the configuration of new nodes is quite a PITA. For that reason a lot of bootstrapping scripts have been built around this [2]. Also, i love the possibility to easily dump the whole (known) network graph and create great graphs from this info [3].
I am using it mostly for reaching hosts behind NAT and creating a secure environment for these hosts.I never have tried the 'connect whole network' feature.
[1] http://www.tinc-vpn.org/security/
[2] https://github.com/krebscode/painload/blob/master/retiolum/s...
It seems that with 1.1pre3 or 4 they have gotten a new, experimental protocol. Hopefully it is an improvement.