Been fine today as far as I can tell. I've had problems during the last 3-4 days though, with frequent disconnects, slow chart update etc...
This is hardly a scientific observation, but I notice if I try to start the eSignal app right at the market open I often have problems with the charts filling. They often sit there with just the price and one single bar, not flesh out for the 2 months plus data. Maybe too many people hitting their server? If I start eSignal like 10 minutes before open, or 10 minutes after I do not often have problems. I only get a disconnect about once a month. This on a very old computer that is due later this year for replacement.