From Russia I am not aware of any English translation of Materialism and Empirio-criticism later than the Moscow: Progress Publishing, 1964; 4th revised edition, 1967. As to the accuracy of the translation I can make only two points. The first is that the general level of Progress Publishers translations is respectably scholarly; secondly, on a spot check the critical academic literature in English on the book, while involving hot disputes about it place in Lenin's theory and practice and his motives for writing it, does not critique the Moscow translation. If there is a devastating critique, I have missed it.
The Chinese edition, V. I. Lenin, Materialism and Empirio-Criticism, Peking (sic) : Foreign Languages Press, 1976, is less seldom cited. The Russian translation may be regarded as standard.
John Eric Marot, 'Marxism, Science, Materialism: Toward a Deeper Appreciation of the 1908-1909 Philosophical Debate in Russian Social Democracy', Studies in East European Thought, Vol. 45, No. 3 (Sep., 1993), pp. 147-167: 163.