The KA11 feels like it has a metal housing to me. Overall, it is more radio and if you intend to actually use the SW (I only use AM/FM on the GP-4L and my Grundig mini300), the PLL circuitry is a good thing to have IMO. I've read gripes about the KA11's receiver sensitivity, but that is probably more an antenna issue.
I've also got the
Kaito 2100 which is a great radio. The nice thing about the KA11 and the KA2100 is that if you load them with rechargeable batteries (NiMH are recommended) the radio has the charging circuitry to keep them fully charged. The KA2100 battery compartment is set up for 4xAA and 4xD batteries. I only have the AA positions filled, need four good D NiMH batteries before those spots get filled.