Reviewer #1:
A good report on a mature work.
The principles, detector, electronics, and testing methods are described in appropriate detail, and the results of measurements are explained and analyzed with rigor.
The few comments are only minor language remarks and typos:
Line 127: typo: "later" -> "latter"
Line 179: "consists in" -> "consists of"
Line 192: "The gains ... is distributed" -> "... are distributed"
Line 224: "The reduced threshold spread allows a lower operating gas gain..." If possible, it would be nice to have indicative gain values before and after equalizing.
Line 284, 299, 484: "showed" past participle should be "shown"
Line 313: "1000 only" in this context "only" means "exclusively", write something like: "... at a moderate gas gain around 1000."
Section 4.8: Very interesting to see first results with power pulsing. Readers familiar with the proposed ILC bunch structure may wonder why you chose to run this test with such lower pulsing frequency and higher duty factor. It may be worthwhile to explain that, and suggest how these results can be extrapolated to ILC conditions.