In the winter of 2009-2010 we built five 16" light-weight Dobs  for myself and some friends. I was just replacing a 12" travel scope with something that had a little more light gathering power, yet still folded up into a very small package so it would fit into a small storage bay in our motorhome.  They all weigh 68 pounds, and fold to 22x22x19" high, yet are very solid and offer great performance.   A 16" is not a big scope, but it sure outperforms the 12" in every way. The first photo shows the scope set up in the AZ desert recently. The rest show the construction of first the prototype, and then the other four scopes.

If you would like to learn all the thoughts and reasoning about how to design your own dream Dobsonian, read The Modern Dobsonian.