Well basically, everything has already been said, but let me express it in my own words again though:
Really a hilarious episode!
Ash, Dawn, and Brock have restrained themselves today, but Team Rocket was the more funny and created a bunch of priceless scenes. I can't enumerate all of them, because one hilarious line or scene was followed by another one almost without interruption. Nevertheless, I want to mention things like "If you can't see south of the borderline..." or Meowth's reaction after he had realized that he had to team up with Team Rocket's clumsiest Pokemon, which all made me crack up.
As most of you have already pointed out, the nostalgia involved was a great, welcome surprise. A reminder of the past once in a while(!!!) goes down well with most of the fans.
But you mustn't forget either that the DP episodes surpass all previous ones and that Sinnoh was the starting point for episodes and plots entirely without precedent.
I appreciate references to the past...but please not too often.
The new Team Rocket uniform (as well as their jet-like car) was terrific! I wish they wore it a bit more often, because it would make them appear more serious. But on the other hand, who wants a mean, threatening Team Rocket in every episode? Thanks God the writers have given the three a new role which in my opinion is funnier, more complex and better than before.
Altogether, an almost exclusive Team Rocket episode with countless funny as well as really witty(e.g.non-electric proof robot) and mature elements!
Ash was allowed to take a break this time.
7 out of 10 points