If you're willing to patiently spend time tackling the odd(but attractive) GUI, Bryce probably allows for deeper levels of control. However, I prefer Vue for the remarkable qualities of light, atmosphere and color that I can achieve with it. If you're planning on using one of these programs mostly for making Poser backgrounds, I'd suggest Vue. However, if you want to get deeply into using a landscape program as an end in itself, Bryce is probably slightly more robust.