Different flavours of *erb develop differently as ecosystems (merb, terb, perb).
On terb, reviews are less threaded per provider (people love to start new threads), continuity of providers is less maintained (sometimes in the middle of a thread a comment will connect the provider to her previous name elsewhere instead of one history here) and acronyms for agency names make it more complicated for newbies (dd, gg, etc.)
What area of toronto are you looking for?