It is so hard to answer this as so many companies use both. You just have to ask when you do an interview. I work for a couple of companies that made the offer to be a W2 or an IC. I always chose to be a W2, as I have found that you will usually get paid for the insanely under timed projects, instead of the oh well, flat rate, work faster, sucks to be you attitude I have run into with the IC only companies. I also end up with very few under timed projects.