I am going to suggest something that may or may not be true. I just know that its true in my current hometown, and it “might” carry over to Vienna. A Vienna resident may know of flaws in this and if they step forward we both learn. So, no issue with that. Most of the great venues in the world have become major tourist attractions, which is great as it helps to ensure that the fine arts survive.
If you are an opera or a music aficionado it really doesn’t matter how many tourists there are as you will be going to where you believe the highest quality performance exists, tourist or no tourists. If you are like me, you may have some understanding of quality but it’s as much about cultural events as it is the absolute performance quality. For the best cultural experience, I want to be surrounded by locals.
This is how I would approach it and on my two experiences in Vienna it seemed to work for me; but admittedly the results of two experiences are not fact, it’s anecdotal.
I look for Friday and Saturday evening performances. That’s when working people (locals) can go and those are more likely to be the days for Subscription Tickets (what only locals buy). If it’s a premier of a production, that’s the most ideal. I look as far in the future as possible and look for one where most of the best seats are sold out, again, I suspect more locals. Of course, I think more of the standing room being sold out is also a sign of a lot of locals. I did a little study at the Oprea and other theaters in my hometown and the number of tourists on the nights I describe above was significantly lower than in the mid-week; and from my point of view the resulting experience is very different.
Then yes, for sight line and for the company, I would buy the best seat I can afford. At 220+€ a seat for the best seat in Vienna I can’t do the best, but I try. Still, for me, even a cheaper seat on a night with more locals will be more of what I am looking for than the best seat with tourists on both sides of me. If I have a question about the quality of the seat, I know that I can click on it, then in the upper right corner of the page see a seat preview button and I can see the approximate view from the seat before I buy it.
Of course if none of that works with your schedule and you are in Vienna, the heck with it, you still gotta go. Its that good.
For many, one of the beauties of the Opera in Vienna is that they encourage you to come as you are. They define not sufficiently dressed as “flip-flops, an undershirt as a top or very short shorts”. For the RS crowd that travels for a month with nothing but carry-on, Vienna is perfect; polo shirt, jeans and tennis shoes it is.
A Vienna resident may know of flaws in this and if they step forward we both learn. So, no issue with that.