The spousal unit put in a clawfoot tub when remodeling the master in our last house. However, it was on a slab, so floor flex was not really much of an issue. Sounds like you are on pier-&-beam or 2nd story?

Be sure to select & price out the fixtures before committing. It's quite a bit more money. Because all the plumbing is exposed, it all has to be finished in chrome/nickel/whatever, and the price is accordingly higer.