Warren, you're experiences match my experiences.
I started using Blockhead-style poppers this year, and caught a lot of nice Largemouth Bass and Smallmouth Bass on them.




I've also done well using Mohair Leeches and SimiSeal Leeches, which are very similar to the Chicago Leech you posted.

For Catfish...I've caught them on a variety of flies, from bass poppers to Woolly Worms/Woolly Buggers and Boa Yarn Leeches, and even microjigs. I've caught some nice ones on baitfish imitations, including 3 cats over 23" in about an hour, just casting from shore in a local reservoir.