I have the 17*, the 20* and the 23*
I LOVE them all. I have LOADS of confidence at address with them, I can shape them both ways and I can even hit them High or low when required. They are great off the tee, off the fairway, out of the rough, greenside chipping and I've even hit them out of flat fairway bunkers!!
My irons start at 5 now, with the 23* clk replacing my 4 iron and the 20* replacing my 3 iron - I would NEVER consider going back to hitting long irons again!!!
I now have a lovely graduation between all my clubs:
8.5* driver - 13.5* F60 3wood - 17* - 20* - 23* Fli Hi CLK's