Tungsten or brass beads?
I often get asked that question during my tying classes and demos and my answer is that it depends.
With the cost of everything going up around us except our pay checks, it's hard to encourage people to splurge and spend the extra money on tungsten. But there are times that it is important to do so. I tell people that if I know I will be nymphing with split shot on my leader, I can adjust that weight to get those flies down deeper where I want them to be. If I lose them to fish or rocks, it's not as painful on the wallet.
A 2 Bit Hooker is a great dropper pattern that should be tied with tungsten beads. A regular Hare's Ear is a pattern that I normally don't use as a dropper, so I would tie that with a regular brass bead and fish it deep with split shot and another fly. If you are trying to figure out what patterns to use tungsten on, just remember, if you want to catch fish on droppers, use tungsten.
If you nymph a lot, regular beads will work well and losing them on rocks and snags doesn't hurt as much. Now remember that there are exceptions to everything and I do use a lot of tungsten beads on my nymph rigs. I mostly use them on bigger stoneflies and anything I need to get deep in higher water in addition to split shot.