I've prefered homebrew yarn indicators for the past several years. Very inexpensive to make, come in all sizes and colors that I like, stay where I put them, last a loooooonnnng time, and float "all day" with only a small amount of floatant at the start, and in any weather.
The owner of one of the shops in Missoula gave me a small thingamabobber the other day to try. Yes, indeed - easy to put on the leader, seemed to want to stay in place, floated very well with a couple small nymphs on, very visible ( light pink ), and lasted about fifteen minutes until the leader caught up on the edge of the shelf ice and I had to break it off, including the thingamabobber.
George told me he uses them regularly. The only thing is - the banks of at least one famous Montana river are brightly decorated with a huge number of them. Makes me wonder what the long term impact will be to the aesthetics of the places we fish, even if no impact on the fishery itself ??
John
P.S. I had a good laugh the other day. Watching a local fly fishing program about the Big Horn. Ancient and venerable local guide explaining how they had to use 9' of tippet out past the indicator because all the fishies there are indicator-aware and indicator-wary. He didn't specify what kind of indicators.
The fish are always right.