I have the Madeno steering wheel spacer in my car with the OEM (Cup) wheel. It doesn't look naff, in fact, your can hardly see it if you don't know. I think it drastically improves the driving position. Before I felt like i sat in the car with either my legs bent or my back hunched. Or a little bit of both at best.
I think they don't advertise the mod on their site because they're not too keen on DIY fitting, since it requires disconnecting and reconnecting the small wiring loom for the airbag. Although it's quite easy, you might end up with an airbag that doesn't work or with one that does......in your face while fitting if you don't know what you're doing .