IMHO it really boils down to two things, what are your needs, and what will you do to meet them.  You want to make large prints (11x14) that can be done with any imaging software.  I think you need to ask youself: do you need powerful rendering abilities?  do you need to have a program to create and render hundreds of thousands of plants? do you need powerful material editing functions?  If so, then Vue will be a great step in that direction.  As far as the second issue, you might find yourself wanting to upgrade your computer if you begin running into memory issues wiht your current computer.  But I tell you, once you get Vue you will keep expanding your scenes, putting more stuff in them, making them more complex simply because it has that power--so you will ultimately need to upgrade.

The interface is slick, but like anything else, it takes familiarization.  If all you want to do is render glass spheres over bodies of water then Bryce will suite you needs just fine--but if awesome realism is what your after then Vue might be the direction you may want to head.