Opinion Polls were coming slowly to me, so I decided to go out and find the fastest way to get them. Most people were suggesting going to an anarchy tourism base, but there are only three tourism anarchy systems in the bubble, so that seemed too restricted to me.
Instead, I headed over to my nearby tourism(non-anarchy) base and tried it out, and quickly found you don't need anarchy at all. Here's what you do.
First off, find a tourism base with a lot of one-room cabins. Each one of these will have a data pad, each with a chance of having an opinion poll.
Second, if possible, find one with a central Bar. Those are very handy because you can freely scan people from the top window without being seen. Also they often have a data pad inside you can check with no security clearance at all.
Here's an example settlement, and the layout I used, as well as my route.
View attachment 288892
That's it. All you need to do is drop in on an APEX shuttle, scan a level 1 access, and proceed to run from building to building, dodging security as you go. Don't worry about stealth when inside the cabins; just sprint up to the data pad and check it for opinion polls. Most of the time, there won't be any, and you can turn around and sprint back out without them becoming more than alarmed. Repeat for all cabins in the area.
If you DO find an opinion poll, just sit at the door watching their movements. Sooner or later, they'll start walking towards a position where they can't see you. During that time window, quickly stealth up to the pad and download the data. It only takes 5 seconds, so you will have more than enough time if you move quickly, and the data in question is rare enough you won't need to do this very often.
The key here is not stealth, but SPEED. You want to be moving constantly between buildings. You want to call your apex back out BEFORE you finish, so it can be waiting for you when you get done. Once you're done clearing the settlement, get in the apex to somewhere local - doesn't matter where - and wait until you're ~50km in the air, before redirecting back to the ground. It'll turn around and respawn the instance, and you can do it all over again.
As you do this, you can often grab other materials as well. Focus on (encrypted)Computer Chips and Graphene, as they can be traded for other things. By the time I found 3 opinion polls, I had over 100 of these three, which is enough to trade for full suit upgrades.
And pow! That's it!
Honestly, my only real criticism is that not enough missions take me to these bases. I think that if I were raiding them more often, I'd find plenty of opinion polls just playing the game.