Our J42 campaign is nearing the end of the second day [EDIT: third day, thanks Storm!], with one day remaining. We have learnt a lot from this campaign, with many minor fixes and some major fixes made to the hosting systems, to HSFX, and to SEOW itself. It is good to review some of the things that appeared here in SEOW large-scale campaigning for the first time:
Cumulative Ship Damage
Apart from one or two minor issues, this has worked remarkably well. In fact it is a crucial part of Pacific and Mediterranean operations now, with human pilots regularly scoring damage hits on shipping, and occasionally scoring kills.
Command and Control
CC functions were included in J42 templates at a relatively late stage, and this has caused a steep learning curve for all. Thanks to good feedback from commanders, the feature has evolved and is now a valuable part of the ground war.
Submarine Operations
This really is a first. I cannot remember a campaign set where subs featured so prominently. They have been critical in the Crimea, Midway and The Slot. Charlie and I are aware of the problem in destroying submerged submarines, and we are considering an HSFX mod to address this issue.
Spies
Again, these are being used widely in some sectors, with great success.
Radar
Initially we thought of radar as a "wonder weapon". Well, it is! But with clever tactics its effect can be minimized, and both sides have begun to realize this and adapt in creative ways.
SOG Production/Logistics
This is an old feature being used intensively for the first time, with a high degree of difficulty. Both sides are having to come to terms with limitations of supply and reinforcements, meaning that they are having to use antiquated equipment in specialist roles. This is stressful on pilots, but there are still ways to be combat effective even in the least preferred airframes.
Trains
Some early bugs in rail networks seem to have been overcome, and feedback is that trains are a valuable way to move freight over long distances quickly and economically.
As J42 commenced, attendances were very high, but have since dropped somewhat, and have levelled off at a still strong amount. It is unavoidable for some pilots/squads to be lost in the initial stages as teething problems and the true nature of the campaign become to be appreciated. But we have been solid now for several months and the signs are that this will be maintained over the last two months of the J42 campaign.
Overall, over 4500 individual pilot sorties have been flown across 9 sectors, in all weather conditions, night and day. Here are some summary statistics:

* Infrastructure kills include industrial assets, bridges and supply drops.
Cheers,
4Shades