I've been using REDI+ for a couple of months now, I've been pretty impressed with the overall experience. I especially love the quick update bar on the level II. That really can make a difference with changing an order, unfortunately its a feature that really can not be appreciated in the demo mode because its not enabled. But take my word for it's pretty quick. As for the charting, yes, it is lacking, but what the system makes up for in speed and stability I can manage. However, it does link to my realtick charts.
It has had its minor problems but like any system, who hasn't. I came from realtick, and that seemed to go down far more often.
Overall, I've been pretty impressed with the system.
Another great feature on the redi+ is the access to the e-redi product, which is really great, if you are on a laptop away from home.
Hope it helps.