Trying to decide between two bags now.....

The Integral Designs North Twin and the ID Renaissance

Both are the same bag construction, same design, just one is a 20d bag and the other is a 10d bag.....of course with that comes a bit of weight and a bit of bulk difference.

Thoughts on the best choice? I have a -30C bag for really cold weather stuff. This bag will be used in summer to early fall (possibly end of Septemberish). Am I better off with the 20d bag and a liner at times, or the 10d bag for all use?

http://www.integraldesigns.com/prod...CFTOKEN=45601115&mainproducttypeid=5

http://www.integraldesigns.com/prod...CFTOKEN=45601115&mainproducttypeid=1