I know I shouldn't buy a flexible holding tank because they smell and can leak. Go ahead, ask me how I know....but now that I've decontaminated myself, my boat and thrown out that damn rotting bag of filth (it was 25 years old), I realize there isn't enough room to install a proper solid tank in it's place under the bunk. I can't seem to find any other suitable locale for a real tank without necessitating long hoses and exhausting installation...really, I just want to go sailing, so I'm back to the bag-of-yuck idea again. I see 2 companies, Nauta and Vetus, that make them. Can anyone compare these two products? I'll probably replace them properly in a few years regardless, when I have a little more courage...