Which is the difference between this outlet and the Orlando’s Premium Vineland Outlet? Which one is more convenient?

I prefer Orlando Premium. More shops and offers. Vineland os like a Smallville Premium with less shops.

I'm not sure regarding the difference I think it might be a question which you will need to ask Google or perform your own analysis by looking at the relevant site maps. Personally I thought that they were pretty much the same (to the point that I didn't really realise the difference). Both had plenty of stores with plenty of items. The answer to convenience would depend on information which only you hold such as where you are, where you wish to go after visiting the location, what you wish to buy & what form of transport you are using. My advice would be to ignore convenience, ignore Google and even ignore other people who have been. Pack a bottle of water, some money, and a pair of headphones for your phone so that you can listen to music (no pictures, no texting, no selfies just music) and just go to the outlet stores and have a look. Visit one outlet store first and then visit the other. I did both in 1 day so I'm sure you could too.