Probably, relative to scalpers. I only do about 1-5 stock day trades a day (several hundred a year) for the past 3 years. I'm sure other's experience with IB is different, on my trading frequency they "only" drop the ball on me a couple of times per year. Maybe I've been "lucky"
I trade a lot and have had very few issues with TWS --- almost none that stopped me trading. I run a technically clean PC though and have a great ISP.