Good discussion.
My experience was that the #3 tip and needle worked best for me (Paasche VL). I used the #1 for quite a while, but I found that I needed to be very specific about all of the various settings (ie. paint thinning, air pressure, etc, etc). When I switched to the #3 setup, I found there was a lot more lee-way with all of these things. The results I got were actually better and more consistent. The #1 tip can do more 'fine-line' work, but my painting requires very little, if any of that minute detail work.
If you're just starting off, I'd recommend going with the #3 setup. I expect you'll get better results and enjoy your painting more. As you understand the dynamics of the various inputs (ie. pressure, consistency, etc), then slap on the #1 and see how fine-line you can get!!
Just my experience.
Murray