I have fished wiggle nymphs since 1986 and they do indeed catch fish. I have a special jig made to bend wire to tie the tail portion of the fly to eliminate the use of a second hook that must be cut off. My nymphs also don't have the open gap in the middle like the ones shown in the above link.
There are flies that will do better day in and day out that are easier and quicker to tie. An important attribute when fishing for steelhead or tieing flies for the commercial market.
fishbum