Books by Grigory Petrovich Klimov.

I'm actually interested in people's opinions about the latter.

You should read "The Case for Zion" by Douglas Reed instead.

http://www.hrono.ru/libris/lib_r/rid00.html

It still contains factual material and is more grounded in reality.

Klimov's work is fiction for unstable people. It exaggerates too much, with many one-sided points without relying on statistics... It's just emotional reading and hardly deserves an evaluation.