Slicks? Dunno. I use the same tyres all year round so theat could be interesting! I'm sure that it is possible to get a dodgy batch.
Take those Luganos for example. Both mine had a fault that felt like the bead wasn't seated properly. The whole bike shook like mad. 30 miles and then straight into the bin.
My Luganos have been great in use, but I did have to replace one when the glue holding the treaded part on became weak and the tread lifted. Made no difference to the ride though. But "wobbly" is an odd quality and I have not come across that before. Do you remember what pressure you were running them at?
I have Gatorskins on another bike, and as durable and puncture resistant as they are, the do feel a bit numb on the road.
I was reading an article in one of the cycling mags and it seems that the pro peloton are using 25mm tyres rather than 23mm which is interesting, so does anyone know of an amberwall 25mm tyre? If it puncture resistant, light as a feather and cheap, then all the better...