Martha,
I did not replace the floor of the tent with cuben. I didn't do it mostly because of the cost and because I didn't think I could do a good quality job of it. I could have just cut out a big rectangle and left the bathtub walls, but I don't think that would have been a very professional job. Removing the entire floor would have involved sewing cuben to bug netting (which I've never done) and re-attaching all of the corner tie outs. Overall, the expense and difficulty deterred me.
I did get replacement poles. I measured the length of my poles and bought a new set of carbon poles from Fibraplex. I was quite happy with the weight of the poles. On one trip I encountered some fairly high winds and moderate snow fall, and these poles were too flexy to feel confident in those conditions, but for normal 3 season use they would have been fine. So overall I was happy with the weight and cost, I just wouldn't use them in harsh conditions (which can't always be predicted).

