Interactive Brokers historical backfill services can be unreliable but they do work. The problem with IB backfills is that IB is occasionally non-responsive to a download/backfill request. Additional requests have to be queued, awaiting the backfill in progress to complete. When IB is non responsive, the queue of awaiting requests essentially waits and waits and nothing appears to be happening at all. The DTN MA historical service is fast, accurate, highly responsive. Further, Investor/RT is mutli-threaded with DTN MA so that up to 4 simultaneous backfills can be ongoing at one time, great for fast backfilling of many symbols at startup. But if you wish to save the $15/mo and have minimal need for quick and reliable backfill then you have to play a more active role in cancelling non-responsive IB backfill requests. If you sense that IB is non-responsive to your backfill requests then you can use the Cancel Download command in the IB menu within Investor/RT. Often this will break the logjam and allow other waiting backfill requests to be initiated and complete normally. If your needs for backfilling charts are minimal/occasional, this is not too inconvenient, but if you frequently use backfill, we strongly recommend using DTN MA for the best user experience obtaining historical data.
