My opinion is that we are predictable and deterministic, but we choose to cling to the idea of us being more than that because we can't deal with the other option. The other option is quite simple, from what I see: we'll never manage to completely read, simulate and predict a complex system like our body, so in reality nobody will be able to predict what we'll do - and for me that's enough to feel comfortable. From what I see free will is defined by others as some kind of magic process through which our decisions are based on some random factor which is unpredictable. I'd say the randomness doesn't need to exist as long as the unpredictability holds.