I have Complete and the same size system on Vista 64 as thefixer has, I import from Daz and don't seem to have too much trouble. There is a more dynamic importing option with Poser but I just use export to .obj and it seems to work fine. There is a forum specifically about Poser importing over at Cornucopia a browse through there should give you an idea of typical problems.
Complete has about half the plants Infinite does, there is a package deal at Cornucopia to buy the rest of the plants Infinite has for $199. I took a look at it and decided it was more cost effective for me to just buy the few I want individually. With the occaisional free voucher it's not too big of a deal. Most of the best plants are from independant makers so that's where most of my plant money goes anyway. There are plenty in teh COmplete package to get started with anyway. If you have a bunch of plants for Poser (like those from Daz or RDNA) you can export them as .obj and then import for use as static objects in Vue. It's worth it for some types like flowers.