Info from two sources, one living in New Zealand says that Felt soled boots will not be permitted into the country as of beginning 2010, or earlier.
I have Aquastealth soles [w/o studs] on LL Bean boots - very happy with grippyness, but I am not a very aggressive wader.
Good friend recommends not buying waders with a fly - you'll NEVER buy a pair without again.
My local fly shop, Central Coast Fly Fishing has been discounting his felt soled Simms boots - might give him a call on Tuesday....
http://www.centralcoastflyfishing.com/
Goood luck!