I believe both are equally important, as having low spreads might be great for scalping purpose or even news trading, but ultimately we need to have skills to manage things. This is why bonus can be slightly better to help us in working, as it can help us with good money management. I work with FreshForex where I get it all with having 101% deposit bonus which is use able while even the spread is absolutely low, so it all works for me at one stand.