But you need a backfill each time you want to load data for a new symbol? Right? Is it similar to Quote Tracker? Do they have historical charts?
It all depends on how you trade! I use Sierra & IB.. HQuote pro to get historical data.. Sierra can read a text file of historical data, doesn't matter how you get that text file. If you are still in the experimental stages, and think you'll need to look at a lot of different things (SOX, TICK, adv/dec etc), it's hard to beat QCharts for about $100/mo once you add the real time exchanges. I used to use it, but once I found all I really needed was a few candle charts, I went to SC to save the $90/month.