On the practice board I noticed some issues when I tried to do a set of nearby components at the same time. If I got too close with the hot air, it would occasionally blow them around a bit even with the air turned all the way down (I'm using an 898 from eBay, for whatever that's worth).
This whole process really is like magic. I've done plenty of hand soldering and I'm perfectly mediocre with it. This allows me to do things that are a fraction of the size with exponentially better results and in less time.