Does specialty dining fill up? +TA credit questions

[jbrinkm]

Can I just wait until we're on the ship to make a reservation for specialty dining? (Giovanni's, specifically, on Allure) We've never done specialty dining before but we're getting a voucher from our TA for our upcoming cruise. DH and I have $50 and the teens have $50 (one for each room). We're pescatarian so we've looked at menus and decided that Giovanni's is our first choice.

1. Do we have to wait until we're on board to book?
2. Should we be worried about being able to get a reservation?
3. How does the voucher work at Giovanni's?
4. Do the kids have to go since one of the vouchers is for their room?
5. I've seen people say that they book beforehand then switch payment method on board - is that easy to do? We have an additional OBC of $50 per room - if I make the reservation using my OBC, would it just go back on my account when we switch payment methods? 
6. How much is Giovanni's typically? Will a $50 voucher cover two of us or should we expect to pay extra?

Thanks!

[ChessE4]

When we received specialty dining vouchers from our agent, we couldn't make reservations until we were on the ship.  Some restaurants were unfamiliar with them, so bring them with you to show the dining room staff.  No problem getting a decent time, but your experience may vary.   These were vouchers for a free meal, one lunch and one dinner; there was no "cash value" associated with them.  Your vouchers seem a bit different.

You can check a la carte meal prices in the Cruise Planner -- they have gone up over the last year.  We have opted for lunch meals when we pay out of pocket -- still great food but one half the price.  Expect a dinner to cost around $50 or more, so one voucher at best does dinner for one person (again, check Cruise Planner or the Royal App for your cruise to see current price).  Lunch at Chops for us was about $25 each for us in November.

If you decide to order an extra meal pre-cruise through the CP, you don't need to pay with your OBC.  You can pay with a credit card, or part CC and part OBC.

I don't know anything about switching payment methods on the ship -- likely someone else can comment on that.