The Dunlop 211's are sport street and track tyres, something similar to the Pirelli Dragon's, but they are a more modern tyre, with sportier looks ans ride. Very good option if you want a tyre to do trackdays apart from street riding.
The 212's are more track focused and more or less, the best threaded track tyre you can get. On the plus side, they provide extraordinary grip compared to any other threaded tyre on the market. However, they are not suited for everyday road riding. They don't have grip when they are cold and you need to be extra cautious on that.
One more thing, the 212's are very sensitive to the tarmac temperature. Each time you get to the track, you need to have the appropriate compound based on the track conditions, otherwise -especially the rear- will get destroyed pretty quickly.
So, if you are just a hobbyist taking to the track in the amateur group, the 211s are the best option. In case you are more serious about the track riding, get the 212's and you will have extra fun.
Tyre warmers are a must for the 212, and seriously nice to have for any sport track and road tyre.
I ve tested quite a lot of tyres in the past (except for the Bridgestones) and the Dunlops are, hands down, the best you can have.