You are not really "switching" to PADI. You are just doing additional training with PADI. Switching would suggest you give up your SSI certification which is not the case at all. If you want to do specialties, PADI is hard to beat for availability and variety.
Take any training you want from any agency you want. If you have future plans of going pro I would stick with PADI but if not, it doesn't matter.
Take any training you want from any agency you want. If you have future plans of going pro I would stick with PADI but if not, it doesn't matter.