Many people were using it until they changed the api effectively breaking our "voo-doo" machines. It sounds like you are just going to do another form of voo-doo, not unlike our charts...
RyNinDaClem, what is the general idea behind how you trade? As far as I know systems are never profitable. I use math to analyze the past and make predictions on the future. Then I backtest to see if my predictive models would have been profitable. If you call that voo-doo, then yeah, I luv voo-doo.
EDIT: I don't get it, they changed the API and broke your machine... are you doing something chart based? If its chart based why do you need the API and numbers?
Yes, I use Sierrachart and a feed by slush (kept up to date by Deepceleron). The feed automagically grabs all the data in real-time and sierrachart plots it out with momentum indicators, moving averages, volume, etc...
As far as my system goes, I don't use a pre set system, per-se. I use a group of indicators as my usual go-to visual aids. But I always check other ones to further confirm what my usual group is telling me. The market is ever-changing so you can't use a static set of indicators, and you must adapt to the changes.