We have central vac and it is amazing. Yea you have to "haul the cable" but that is a lot less work than moving a full sized vacuum around the house. Basically there are 3 main plugin points in the house. From those 3, you can do 90% of the rooms in the house. There is another plugin point in the master suite. From the one upstairs plugin point, you can do the entire stairwell, 2 bedrooms, a bathroom and a hallway without carting anything around. Suction is plenty powerful. I'd agree with whoever made the suggestion to at least put in the piping.
And why wouldn't you install Cat6 if you've already gutted the walls? How expensive is a few runs of cable? I did someone's house for free and that was when the walls were already in place, had it been gutted it is practically a no brainer. Something like fiber on the other hand would be more expensive, but still damn nice to have. At the very least it is good to have a few spots within the house where cable runs so you can easily wire in wireless signal extenders if they are needed.