Soweit und Bisher.
As far as I can tell, both these worlds mean "as far as..." Is this a correct observation?
If so is there any difference?
There is a difference.
Soweit ich weiß ... = As far as I know...
Bisher habe ich nur gekochtes Fleisch gegessen = Up until now, I've only eaten cooked meat
Soweit mir bekannt ist... = As far as I'm aware...
Das war mir bisher nicht bekannt = I wasn't aware of that until now