one important issue with chartsdata is , whenever there is a disruption, either through power shutdown, or internet connectivity losses, then if you are using odin to fetch futures data, till the time you get it up and running, there will be data holes.
For futures , I believe there is no backfilling as yahoo backfilling gives only equity cash data..
Provided you have a facility to plug those holes through some other source by backfilling future quotes.. buy sell decisions taken with data holes will not be a correct one..
This is most important and must be taken care of..