I trade with IG markets.There quotes on asx stocks are exactly the same as the real market.When a buy sell moves so does the pprice on ig.Its identcal.Your buy sells arent in the real market though unless ig are hedging there bets.
With indices,oil,gold etc no comission just the spread.They make there money by spreads,interest on long/short position.comissions and probaly the most by people losing all the money in there accounts.
Thats the way I see it anyway.If you beat the market you will make money from IG.Its not rigged or anything as far as I can see.Otherwise they would have no customers after a while.Ive made money from iG and if you withdraw money its in your bank the next day 2 at the most so cant complain.
And I dont work for IG and have nothing to do with them personally.I havent tried any other CFD providers so cant comment on those but ig seems as good as any that I looked at price wise,