Honestly at this point you're better off going to a Verizon store on the 21st at 8am that is located in an area that is not too populated.
On the 14th when they were taking preorders, it was better to preorder from Verizon simply because it was easier to chose plans and you could transfer upgrades. Also less people were going to Verizon's online website so the website was working just fine.
Most people avoid Carriers to go directly to Apple. If this was in January then I would advise you to go to Apple but since your number 1 priority is to get the phone then I would advise you to go to a Verizon store.