The only problems with Berkey's that I know of were some black elements with bad candle-to-stem glue connections. Some of these came apart. That problem's been resolved a long time ago; maybe a year or more now.
I have a big Berkey and also bought one several years ago for family members who...
my waffle iron distributes the heat evenly and cooks the dough well. Don't forget to heat both sides of the waffle iron well and lubricate the first waffle. It sticks when I do it without oiling.