It all becomes clear at last!
Being a guitarist for 10 years, and switching to the bass 6 months ago, I found it quite easy to pick up using my trusty pick. However, all my bass playing heroes (Steve Harris, Cliff Burton, Geddy Lee...) use finger picking, so naturally this is the sound/style I want to emulate. After months of persevering, I found I was struggling with keeping time and speed on fast passages. This morning I was practicing, and for some reason starting playing a lot more 'softly', brushing my finger tips over the strings instead of 'digging in' as I have always done before. Wow what a difference it makes!! I have to up my amp volume slightly to compensate for the softer approach, but I can now manage 16th's at 150bpm consistently and comfortably. It's been such a revelation, my playing has improved 200% in a matter of hours.
I just wanted to share this to save other novice players making the same mistake.
Let the amp do the work, not your fingers!!