Most tournaments of the European Go Congress 2015 (Liberec, Czechia), incl. the European Go Championship, the Main Tournament, the Weekend Tournament, most side go tournaments and many casual games, used the AGA Rules (except where overridden by the EGF General Tournament Rules etc.). On my personal request, Ales Cieply clarified that that meant using situational superko.

He justified the use of AGA Rules because of many players from various countries with different rules backgrounds, incl. Chinese players. I can confirm this by my own experience in my Rapid round 1 game against a young Chinese player. Counting started by his removal of a few stones from white territory and waiting. After a few seconds, I realised his intention: he wanted us to apply Chinese Half Counting, he had created a multiple of 10 of empty white intersections and then implicitly, averbally (maybe he could hardly speak any English) expected me to perform the second part of the counting by counting the white stones then remaining on the board and declaring the winner accordingly, what I did. With AGA Rules, this practice was without problems (for me, who I know the basic theory of Chinese Half Counting but have not, or hardly ever, used it for more than two decades). Thus the counting could be done without any need to call a referee. With some other rulesets (maybe Japanese style), my opponent's Chinese counting start combined with the language barrier could easily have needed a referee's intervention.

AFA I have seen during the congress, AGA Rules were applied well or reasonably by most players with the following occasional exceptions:
- Recompensation for handicap stones in the case of area counting (but not in the case of territory counting) was a new concept for many and everybody had to learn exactly how to handle it correctly in the side tournaments using handicaps.
- Of course, a few players did not listen to or read announcements and so failed to become aware of AGA Rules being used, or they realised this only at a later time during the congress.
- Not everybody learnt the pass stone rule immediately. A few more needed more time to learn the White passes last and pays the last pass stone rule. However, most understood the passing procedure quickly.
- A few players tried to circumvent a correct application of the pass stone rules by their own creative inventions, especially if White made the first of successive passes, such as a) paying for the first pass but not paying for the second and third passes, b) executing only the first pass, c) [rare] modifying the komi for the particular game instead of using pass stones, d) etc. There may have been different motivations for this, such as language barrier, seeking procedural efficiency or psychologically compensating a disappointment about having to pay an excess white pass stone.

I have not witnessed any long cycle superko incident but surely there must have been a few in view of the many congress players.

On the registration day, the Japanese held a rules explanation / translation meeting mostly in Japanese. This year, I attended to witness how well AGA Rules would be explained. Although I do not understand Japanese, it was clear enough to me that strategic explanations of area scoring during the endgame were incomplete. Therefore I provided some extra explanations, which were translated into Japanese. They permitted my contribution because, for many years, Japanese congress participants know me as the "Rules Experto":)

Thanks for the info. It's interesting to know what happens when various people from around the world play go together.

In France, we have a variant of the AGA rule, and in our club, everyone uses the case a) that you mentioned. But I heard the president of our club reminding us once that we should give a prisoner for every pass, because our opponent may play another stone after that.

I was at the congress as well and have also had quite a good experience with the AGA ruleset. If I am allowed to comment on a few of your points:

Since the handicap compensation applies only to the rarely used area counting (I witnessed it being used only once: in Robert's already mentioned game), I am pretty sure it was correctly ignored by the majority of players (who knew nothing about it ).

For the "circumventions", all the methods you reported on produce the correct result of the game, where most can be considered an exchange of exactly one prisoner (which is a common practice when there is not enough stones).

For the choice of ruleset, I think that the Chinese main sponsor was probably happier with the AGA rules than with any form of Japanese style rules. Plus, I just cannot think of a more appropriate ruleset: verbal rules are not exactly the way to go, written Japanese style rulesets are complicated and using Chinese rules would require every game to be counted by a referee.

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“Discussion is an exchange of knowledge; argument an exchange of ignorance.” ― Robert Quillen

I didn't know about this, but after having played with a couple of Japanese opponents, I figured out that someone has probably explained them the AGA rules.