Before the new tyres and the controversy over the tyres falling apart, Lotus and Ferrari were the teams to beat.
RBR were complaining that the tyres were preventing Vettel from driving flat out. Rather than using the car aggressively to get the best lap time, he was nursing the tyre, from corner 1.
Merc - the less said about them the better. They got pole in Malaysia (was it) and then went backwards in the race as they had to manage tyres. After the race not a single body in the team knew why they had such a problem. They then had an extra, illegal test and a few races later, they were able to compete in the race and qualifying.
In any case, this season is almost over, so no point in arguing over something which isnt going to make any difference.
Regarding the Summer break: after the Summer break, RBR came back storming - Vettel on top form. This does seem to be a pattern. I'm not sure if RBR even take a break during the Summer, but as DM states, they do have a habit of moving forward while the employees are on holiday. Where other teams seem to stand still during the holiday period. Perhaps Sparky can explain how this works?
Kimi got 98 points to GB, and 90 or so since, Grosjean got 26 points to GB, and 90 since? Are Lotus really doing worse, Grosjean certainly isn't, Kimi had similarly bad results in the first half of the season as he's had since.
Lotus has been second best all year, they have a few tracks they sucked, a few they were so good they could genuinely compete with RBR, no different to last year, they were the most inconsistent in terms of car vs track last year, and this year. Grosjean sucked balls first half of season, drastically improved the second, Kimi went off the boil but motivation/morale and fighting with the team + bad back clearly had a huge effect there, and some bad luck with his DNF.
As for Merc, they won their races and improved race pace almost straight away, not when tire testing was done and MILES before the new tyres were used in race.
Hamilton, lets see, I'm going to list how many places Hamilton went back in the race from grid to finish in order(just the number to make it shorter) 2, -1, 2, -4, 10, 2, 1, 3, 4, 0(his win), 2, -3, 0, 3, DNF, 3, 3. Outside of the Spain race... I see no difference. People are acting like Spain, the absolute one off where he went back 10 places and Nico went back 5 places, was the "norm" it wasn't it was a massive outlier. Since the new tyres they've picked up less points(just), not won since Hungary and looked less competitive in qualifying.
All year from the start they've mostly gone back 1-3 places, with a couple going forward and Spain hated the car, hated the tyres hated the drivers. Spain was absolutely a one off, it was not the average situation at all, if they raced at Spain now, same would happen.
Outside of driver differences, the cars haven't changed much at all since the tyres. There is the odd race Sauber look super competitive, others they look crap, same for Force India and even Mclaren now and then. Merc look podium capable at tracks with better tyre wear and they get a bit of luck, otherwise they go backwards, Ferrari only really do well at tracks lotus/RBR aren't so good at IMO, RBR get better throughout the year so other cars are competitive with them depending on track early on but RBR move so far ahead by mid season even at their "bad" tracks they are too fast.
I just can't see where Lotus scored 100 points before the new tyres and like 10 points since, there is almost no difference. Kimi isn't the best qualifier, with one start above 4th. Grosjean didn't get a 3rd on the grid till Hungary, and has matched that a couple of times since. They've been top 3 in 5 of the past 6 races, podium in Hungary. Podiums, number of races one or both has been top 4 , number of races both cars were 5th or worse, I can't see how the second half of the season by any measure has been worse.
There has been three races they didn't get a podium second half of season, four in the first half of the season by my count. More points, more podiums, less bad races, only difference is Kimi got a single win in the very first race.