Pepperstone is one of the brokers I am considering (my plan is to expand to 2-3 brokers to spread my "broker" risk) - I've heard good feedback about them both here and elsewhere.
I've read that MT5 is a definite upgrade from MT4, both in terms of flexibility/capability but also processing speed. I can understand your comment about EA guys sticking to MT4 because I am in the same boat. My suspicion with others is that it will take some work to migrate EA's from MT4 to MT5 so while EA's are performing well in MT4 why upgrade? I'm sure at some point there will be a benefit to do the migration. In my case, the EA platform I use (EA Labs) only writes code for MT4 hence why I am sticking with MT4. If they expand EA Labs capability to MT5 I will certainly look at the migration at that point in time.
As to your last question I'm afraid I can't offer any insight or references - outside EA Labs I haven't done a lot of research into EA coding/signals.
