I've just done 11,000 Klm's on my third set on the bike and I've got another set in the garage to put on during the week.
They are quite good in most conditions. When new they feel funny as the bike will drop into corners quicker than a pair of road tyres. One gets used to it in a day or two.
For gravel roads they are nothing short of brilliant, dirt tracks, the same.
Bitumen roads are a different kettle of fish. When new, they are a bit flexible on very tight corners as one is braking, the same applies for accellerating out of corners. When half worn they are as steady as a rock, so to speak. However, they are not as good as genuine road tyres.
In the wet one rides the bike accordingly, but that doesn't mean they aren't good, just not as good.
I know that riding on snow over bitumen is better, did that last winter going over a pass and left the road tyre mob way behind.
In short they are now my tyre of choice. Recently I picked up a spare rear wheel. I have fitted that with a Metzeler Enduro 4 which is a 100% steel belted radial street tyre. When going on a longish road trip I now put the street tyre on, for all other trips I run the TKC80 tyres front and rear.
If you do any dirt at all, it will transform the bike. You can point the front wheel anywhere on dirt with impunity, with a TKC80 is on the front!
Mick.