I cant see what the benefit is. Teams who get into the top 10 are now going to have a scrubbed set of each tyre. So you basically getting punished for making it into the next step. Gone of the days of a team saving say a 2 new mediums for the race and a hard tyre, as there will be a scrubbed set.
It also means that you will see less soft compound running. Teams at the lower end of the grid arent very likely to take a large quantity of soft tyres.
Look at how many teams took a soft tyre and there was only the 2 McLarens that run a silly short stint in the race. So any top team would take 2 sets of softs for Q3 (1 set if your feeling brave) and that would be it. Other teams that arent likely to get into Q3 need not bother taking a soft, unless theres a chance of running it in the race - which im sure everyone outside of Q3 will take 1 set for a late safety car. So the rest of your allocation will be took up with the mediums and hards.
Q1 will be interesting, when theres 20 cars doing multiple 'slow laps' to get some heat in the tyres to try and stay on the track and get a decent time in. Likely to see 2 or 3 out laps to get heat in before cars put in a fast lap. Take 1mins 40 (ish) for a slow lap of Imola (soft Q1 time was ~1min:20secs) so if you need to get 2 or 3 laps in its 5minutes before you get your outlaps complete to get some warmth in the tyres, 1mins 25 for a hot lap (5-6seconds added onto last years soft time - be less this year) and then another 1mins 40secs in lap. So thats 5 laps on the hard... 8minutes to get your 1st run in.
If its a case of needing 2 runs, and the same warmup on the hard, you only going to have 2mins in the garage before you need to go back out for a second run.
I think this style of mandated tyres is going to be similar to the shootout qualifying that we seen a couple races back - so will end up being a bit more like Formula 2 qualifying.
Dont expect teams to take more than 1 or 2 sets of softs into a quali/race day now.
Mess with the Bull - you get the horns.