Few points to remember while Initializing from Backup in Transaction Replication

Pros

·       When you setup replicating huge tables with initial snapshot and if you can’t handle it whenever you add articles to this subscription ,Initialize from backup option comes handy.
·       You  can have the  smaller articles grouped under a separate publisher and the huge ones put under different publisher.

·       If something goes horribly wrong with a smaller table, you don't want to have to re-push the big ones just to fix a problem with the small ones

Cons

·       The one downside noticed is distribution cleanup agent takes more longer time.
·       If  there is an issue with huge table publication then you may need to reinitialize the whole backup which may need some downtime on the replicated server