Have used IG for 20 years plus. Always helpful and knowledgeable and above all entirely trustworthy in execution. I did a cable deal the other day where they improved 4 pips on the way in and 3 on the way out in a highly volatile market.
If I have any complaint it's that the mobile phone app doesn't always seem to work consistently even when there is 3G.
Above all the ease of use - whether payments, execution or credit is outstanding.