You can't go wrong either way. Do you want a 6-7 course meal with more options among courses or 12-ish courses that are more pre-set? The QV room is more intimate, but I think the main dining room is a bit more attractive overall.
Either way, it would be a wonderful choice for a honeymoon dinner; certainly the best place anywhere in the area and very near the top of my personal favorite restaurants anywhere. I'm going again in a few days and can't stop thinking about it!
I agree with the PP about doing the wine pairings, whether you're a wine novice or an oenophile. However, they have an outstanding wine list with some ultra-splurge selections that are actually "bargains". Some of their rare/older wines are even below current retail prices.