Is Ninjatrader worth considering? Great charts and easy to use.
I found that it lacks some basic functionality that I desire, but I solved it by either buying 3rd party add-ons or creating them from scratch as a custom script/indicator.
As an example, I'm fairly sure you won't get % change charts on NT, but it should be trivial to solve with an indicator.
The obvious drawdown is that it ain't compatible with a lot of brokers for stocks. In fact, I think Interactive Brokers is the only one. Another drawdown is that they seem slow as hell to implement user requests and complains. In contrast, Sierra is known to fix and implement new stuff fairly quickly.
At a point, I was fairly frustrated by Ninjatrader and started looking into other platforms, but I realized that no retail platform is perfect and decided to just stay with what I know. I run it on a workstation and it's very, very stable.
The one platform I was considering was SierraCharts which seems absolutely fantastic, but, it is said that there's quite the learning curve to get fully up to speed. I decided my time was better spent improving my craft instead of learning new software.
It is free for real-time charts from interactive brokers but you have to use an old version of IB TWS and cannot upgrade.