Of course then you are carrying the expense of both plans for a while.. 😞 And remember that most ports are successful without intervention, it's just we don't see many of those here, we mostly only see the ones were help is needed. The bad part right now is that due to the sheer number of incoming from the promo there is a backlog and what would normally be resolved same day for a failed port is now taking several (a week?).
What I would say is that if your phone is mission critical for you and you can't afford downtime, holding off on the port is a good idea, the extra you spend on having 2 plans at the same time is pretty small compared to the peace of mind bought. If you have a spare phone, or better still a dual sim phone, you can even still use the PM plan for data and outgoing calls (gotta love those unlimited anytime minutes!).
If, however, you can afford the risk of potentially having a significant downtime, go for it as chances are it will work without intervention, just be aware that it could happen.
