Do you have/had a LT? Those things look awesome, but are their HuCard & CD capabilities really bad?
An LT sucks compared to a Duo for playing CD games because it doesn't have a CD-ROM.
The pad(ie: the entire thing) isn't as easy to use as a regular PCE/Duo pad and is 7 times the size.
The first player pad on an LT is always 2 button, but a Duo's first player pad can be 6-button, a joystick or even a PSX peripheral.
Therefore, I'd rather own a Duo over an LT to play games.
As a collectible basing value on rarity, the LT is worth more.
I don't own an LT, but was just outbid for one recently that went for $450.