Not sure about other funding companies, we don't seem to have any issue so far with E2T/Helios. We are running two Rithmic platforms using two different internet service providers with one for myself and another one for her. About two weeks ago, I open a trading account to trade with my own money. I don't see any significant different between these trades from E2T/Helios and my broker.
Yes there are scam brokers. Easiest to detect them is regulation. Brokers that are scammy usually are either not stating on their website by which agency they are regulated (meaning not regulated at all) or they are regulated in a shit hole country like Angola or some Island you habe never heard of.
99% of the paper traders are busy with everything else but real issues concerning trading. In essence, BS. It is a growing pain that traders who don't trade real funds come here and just BS day and night and affect those who actually have skin in the game with theories. To everyone else: Rithmic servers in risk management have many functionalities, but they don't have the ability to slow down trades. A trader could experience slow connectivity for a variety of reasons: Multiple data feeds running, slow internet, inability to receive unfiltered trades (can change to aggregate), and many other reasons that can slow down execution. Risk management systems are different servers than live servers for execution.
If you want to do the most: You can always record the platform using window's game recorder (it will only record that app, not the whole screen, even if the app is in the background), for example, during all hours that the markets are open, whether you are trading or not--always leaving platform open. Long tail hit your stop, and you don't see how that could have happened? Compare chart (or time and sales) of platform with another charting service, tradingview, for example. Free charts will be delayed a little bit. Does the second chart also show the long tail?