Yeah, good suggestions.
General rules about 3d stuff:
1: it takes a lot of CPU power. Especially to render complex effects such as transparencies, volumetrics as smoke, and reflections. If you want these you have to be patient with the render times unless you have just a very powerful computer. I have used Bryce on my laptop... so you can use it just about anywhere. But ideally you should have at least a 3ghz (or 3000+ for AMD guys) or faster processor. It works just fine on my 2ghz laptop, but I have to live with longer render times.
2: it takes alot of ram. I tested it a little, and Bryce works on 512mb. But, it is quite a bit slower. It works pretty good on 1gb, but slows down if you get fancy or go large. 2gb is ideal for Bryce. It is generally faster than 1gb. Above 2gb is for guys with Lightwave, 3d Studio Max or Maya. Bryce improve a minicule amount a 2.5gb, but there is no difference between 2.5gb and 4gb. If you have only 512gb, be patient.... and start saving up for more ram. If you have 1gb, be a little patient and consider more ram if you start to get into the 3d stuff.
3: It takes ALOT of disk space. You can run Bryce on a laptop. I made a unit and 4-5 buildings and other things on a laptop. But, the smaller disk was a challenge. I could not keep incremental saves for long. I would suggest that if you're gonna have some serious 3d fun, you need at least a 120gb disk to leave for just 3d stuff. Ideally a 250gb disk. More is always better. And unlike RAM, you will find a way to fill any disk no matter how big.