I'd not done any classic skiing since March but even if you are mad keen skate skier it is a good exercise from time to time. Classic skiing done well is extremely graceful but also very hard to master due to the weight transfer from ski to ski which requires excellent balance.
There is a school of thought that is against classic rollerskiing as the skis offer a "perfect kick". You don't really have to transfer your weight for the ski to grip. I spoke to a local skier recently who told me she goes out in the rain to avoid this, well she can't ski much as rainy days can be counted on the fingers of one hand in the South-East of France. Oh and I don't like wet feet. Other skiers just double pole as this builds upper body strength and still needs a bit of coordination. So I largely double poled today as I was shaking out the cobwebs with a bit of kick double-pole and very little diagonal stride. That can wait for later. In the end I did my 20km loop in hot and muggy conditions but largely in the shade. I wouldn't really want to go further.