I am going to all Langs and I'm selling my TBHs. I'd be happy to answer your questions but after almost two seasons with no honey and half my colonies dead, I'm done with this kind of hive. You can see the details here:
http://www.beesource.com/forums/showthread.php?p=565669#post565669
http://www.beesource.com/forums/showthread.php?p=565669#post565669