Good converter
Did not noticed any input delay while testing with Soul Calibur 2. It is good converter

Attention fellow Wii DDR players
I bought this so that I could use my PS2 Ignition pad to play DDR Hottest Party, and it works perfectly, with no delays or any other issues. The mapping of the non-arrow buttons is not as expected (when playing Hottest Party, X is "confirm" even though that's where the B would be on a Wii pad, etc), however, all you have to do is figure out which corner button does what and it does not affect gameplay itself anyway.
Will be repurchasing once my first one wears out!

superb compatibility!
I used my PS2 stick to play gamecube games and wiiware on my Wii, and it works very nice! Not to mention the rumble feature also works great when playing GameCube games as well! Absolutely terrific!!

Works as advertised!
Great if you have PS2 pads lying around (who doesn't?) & you don't want to get a classic controller or gamecube gamepad for your Wii. Only bad thing is the weird mapping for the L1 & R1 buttons on the PS2 pad.

Great for Tatsunoko vs. Capcom!
If you play Tatsunoko vs. Capcom (for the Wii) and have PS2/PS1 sticks lying around but you don't want to spend extra cash for Wii-exclusive stick, the Mayflash converter is the best product to buy. Works with ANY PSX controller and you won't have to worry about any input lag whatsoever!