I agree with the above. I cancelled my subscription as well for the same reasons. I write my own code for backtesting so don't really need a nice UI.
Backtesting is seductive since you can engineer strategies that look insanely profitable. But in reality you're just overfitting to the data, *especially* with directional trades - it is a fiendishly difficult problem since you *want* to believe what the backtesting is telling you. To backtest correctly, you need to correct for overfitting, which means testing your strategies over out-of-sample data, and select data from a wide variety of market conditions. It's always a rude awakening when you see your insanely profitable strategy collapse upon meeting out-of-sample data (including in your own trading account). I've definitely experienced this first-hand.
I think there's definitely a lot of validity to momentum trading, but it only works until it the day it stops. I think the trick is recognizing when that day has arrived, and stopping these trades. For me, that pretty much sums up January, since it was such an unusual month given the recent past, at least in terms of the short-volatility trades like the SVXY and VXX strategies. I, like @Yowster, also did a number of post-earnings condors, which worked very well until the very recent past, so I've drastically reduced my position size with these trades. Again, they all look fabulous in a backtest...
In times like these I think it's best to be long volatility and market-neutral until some of the dust settles. I've also been increasing my commodity trades, since these are not particularly correlated to US equities. The beauty of options is that you can profit from any market condition in any market that has sufficient liquidity so it gives you that sort of flexibility.