I own a PCjr keyboard and no lie, it feels incredibly bad; rubber dome with integrated sliders, horribly scratchy and binds on off-center presses, even with the 1u keys. The domes themselves are mushy and hardly tactile. I'd say the key feel is reminiscent of a cheap $0.99 calculator from your local strip mall thrift store, so it's no wonder that the 1st gen board looked like one too.
It's almost comical that this POS came from IBM. What they were thinking only God knows.