The new harder compound was tried in Turkey practice but not used in the race, but it will from Spain onwards, and it's a good move.

Beause we know the teams have been trying to get rid of harder compounds when they can as it's not durable enough to combat the speed difference loss to the softer compound, but now the harder compound will last longer and make the strategy more flexiable to a point where teams are a bit more happy if their on a harder compound. This has been the only missing link in the pirelli tyres so far, and last year bridgestone compounds were pretty much similar all around, so Pirelli will fill the last void, and this perhaps will make qualifying a bit more important then it has been so far, if the harder compound can outlast softter compound by perhaps by 8-10 laps, could change things for some cars/drivers. A two stopper might work better for a faster car/package, a 3 stopper would be a norm and 4 stopper could become rare.

we dont know how good that tyre is yet. but it should be better to have a viable alternative stratagy. some of the best racing can happen when people take alternate choices

Let's see how it goes.

Pirelli have suggested that the new tyre will be slightly (even) slower than the old hard tyre but should have much better durability.

So in Turkey, for example, you would have to trade off a 21sh-second pit stop against a tyre that is almost 2 second slower per lap (as compared with the option), so the options would still have been used by everybody. The difference would have been that the second hard tyre set would not have been needed in the race. But that would hardly be an important difference in strategy.

Qualy, on the other hand, would be different, because only RBR could have afforded not to use the option tyre in the first shoot-out. The rest would not have had fresh option tyres for the race. That may have the unexpected effect of forcing everybody to race on primes, even though they are worse, because nobody has any fresh options available. It would probably depend on how badly beaten the options were after Qualy.

Maybe that's why Pirelli is flotating the idea of having a qualy tyre. Otherwise, they will have to increase the number of tyre sets alloted to each team.

Until we can quantify the difference in grip and durability, I don't think we can be sure either way. Over a single lap the difference between the hard and soft was around 1.2 seconds in China and in Turkey.

Turkey is also slightly unusual in that it has the lowest net time loss for a pit stop of any track. From pit entry to pit exit It ass 21-22 seconds (as you say) but that equated to 16-17 seconds in terms of net time loss.

I think the medium might be their best tire. It will be interesting to see how the strategy works out in the Monaco, Pirelli mentioned that the supersoft is extremely soft and only lasts 7-8 laps.

Canada is going to be 'fun' then. The soft and supersoft have been allocated.
We won't even see the 'Medium' tyre in action until Valencia.

6 stop strategy!