We did Category 5 on our first trip and have done Cat. 7 on the next 3. I'd only go for a 6 or 5 if there were no 7's left, and I absolutely had to sail on that date (or if I could pay for a 7 but get a 5/6). We usually try to book category 7 on deck 7. That way we get the deck we like, but don't have to pay for a category 5.
The verandah does have a partially obstructed view, but I felt you could still sit out there and see plenty. It's also open enough for you to feel the breeze. One of the pluses is that it's more private than the full verandah.