Jordan pointed out the difference between the two earlier in this thread, and if you understand what he's getting at you'll realize that the New Orleans is substantially better.
Try out the ship builder at http://www.tarrif.net/cgi/production/nf_shipbuilder.php and look at how much more armor you can put on the New Orleans.
For example, 5" of deck armor weighs 4611 tons on the New Orleans; on the Portland, 5" weighs 5112 tons. The advantage is tipped back to the Portland for belt armor (although not as significantly), but the New Orleans wins is back again in bulge and bulkhead weight.
Finally, the New Orleans can fit a more accurate FCS (+73 vs +70), has more usable displacement, and has more DP.
|