Forums are like travelling. You see a nice spot and stay for a while, but eventually everyone must move on.

Bryce has been around for a long time, and there has been a large gap between releases. Unfortunatly some people wanted more power and perhaps changed to 3DS , Maya, Vue, Carrara, this list goes on. 
I used Bryce back in the early days, but for me I went on to write music instead and moved away from 3D. But the free Bryce 5.5 got me interested again and I just had to buy 6.1 at the very reasonable price.
I'm not stuck with Bryce though, if I found something that I thought would improve my art, then I wouldn't hesitate. Lets hope Bryce 7 with its 10,000 trees etc. gets here sooner rather than later.