Firstly, we've seen again at close quarters how these Rugby Sevens athletes have attained levels of fitness and endurance that is surely unsurpassed in the modern game. Also that the grand prix-style tour can throw all sorts at them - from heat and humidity and a cauldron atmosphere in Hong Kong one week, to biting cold in Tokyo the next; and that Japan's brave fans will defy any weather, it seems, to come out in support - a good sign six years out from RWC 2019.
We have seen once again why New Zealand stand tall and proud at the top of the men's Series standings with two rounds to play. They may not have won either Cup title on offer over the past fortnight - which will irk coach Gordon Tietjens immensely - but in keeping up their impeccable record of reaching every Cup semi final this season, and going one better in Tokyo to finish runners-up, theirs is still the golden standard, the benchmark of consistency that all others strive to match.
And in doing without the injured Tomasi Cama, Kurt Baker, DJ Forbes and Sam Dickson in Hong Kong and Tokyo, Gordon Tietjens may also, unwittingly, have cemented his next generation of players. Tim Mikkelson and Lote Raikabula provided the glue but Ben Lam, Gillies Kaka, Rocky Khan and Belgium Tuatagaloa have all made breakthroughs.
Ominously, in their first season competing New Zealand's women also lead the IRB Women's Sevens World Series race with one round to play - success breeding success.
And yet New Zealand's men have only won one Cup title this season - in South Africa - while Alifereti Dere's Fijians and Paul Treu's Springboks (and New Zealand's women) have risen to the challenge twice now to win the all-important 'gold medal' match. And that kind of success and 'mental map' may prove extremely significant in this of all seasons, which culminates in the one-off Rugby World Cup Sevens in Moscow in June. In a World Cup you only get one chance.
As we traverse down the Series table, fouth-placed Samoa are clear contenders in any Cup and will be among the favourites in Moscow, while France, Kenya and Wales have also made Cup semi finals in these past two weeks, impressing along with a strong Canadian side.
Promotion / relegation battle intensifies
For Australia and England the World Cup could be season-defining. Both have endured below-par World Series campaigns, England's full-time squad managing only one Cup quarter final appearance out of seven. You sense that Moscow cannot come soon enough, especially for Michael O'Connor's Aussies, who looked back near their best in finishing third in Tokyo.If the top end of the Series looks a one-horse race, the battle to retain core team status next season - and avoid the dreaded promotion / relegation play-offs at the final round in London - is more intriguing.
Australia, England and Canada have all probably done enough now to edge out of the danger zone and finish in the top 12, but underneath them a tasty sub-plot is brewing ahead of the crucial penultimate round in Glasgow.
Spain and Portugal are struggling in 14th and 15th place and will probably have to line up with Russia, Zimbabwe, Tonga, Georgia and Hong Kong in the core team qualifier at Twickenham.
Just above them, though, Glasgow hosts Scotland are currently tied 12th-equal with the USA, both having performed heroics in Tokyo to reach the Plate final with wins over Samoa and Fiji. Alex Magleby's Eagles won that match, which may yet prove a massive result. You wonder whether Scotland will send for the cavalry and recruit any Test caps for Glasgow, or whether the current squad will be entrusted with the task in hand.
Whoever they pick, they will want to win their first two pool games at Scotstoun, against Portugal and England. If they don't, depending on how the USA fare against Russia, Wales and France, the Scots may need to win their final pool game to avoid relegation. And that match is against a team they've never beaten in any form of the game - New Zealand...
