Purchased South Seas in 2009 and have given away some, but I still have a nice clump left. Gave my mom a small 4-6 fan clump 2 years ago and it is a huge clump now. It really increases well and each bloom seems almost perfect. Very few, if any, blemished or misshapen blooms.
I like sturdy scapes and SS's scapes definitely hold up well. I also like the branching which is about 2-3 way and spaced well enough so that each bloom opens nicely. It blooms for about 3-4 weeks in my zone 6b garden usually from mid-June to early July.
Here's a nice picture taken on 6/25/14 showing branching and bud count. Bud count looks to be somewhere between 6-12, can't tell for sure. You can also see how the scapes stand above the foliage and that the foliage looks really good. I have not seen rust on SS.