When you start Brycing it's hard to stop doing things in it. The Interface is SuperFast with a pleasant, antialiased look so you can easily test your ideas and materials/textures. The problem is that you can be stuck at Bryce and get too lazy to learn other, more advanced softwares :-)...you will always think "...but in Bryce it would be so easy to do that!" so you won't learn about displacement maps, Global Illumination, UV Mapping and so on.