They quarrel about Smyslov: some consider that his main strength is tactical skill, other say that he is exceptionally tenacious in defence, and still others assert that the strongest aspect of his play is the depth of his strategical ideas. (p.xx)
The brilliance and originality of Smyslov's attacks, their convincing and long-remembered violence, is rather sparingly reflected [in this book]. The attractive patterns of Smyslov's combinational ideas are also a little lost in the deep scientific approach which imbues his strict comments. (p.xxii, with four examples)
Smyslov in Preface to Smyslov (1958):
It is convenient to talk further about the role of tactics and combinations in the art of chess. A correctly set out game often creates, as it develops, culminating points, when the problems can only be decided by means of a combination. That is why the play of a master must express the desire to combine a general strategic plan with a skillful use of tactics in the solution of the problem before him. A leaning to one side or another, an excessive subjectiveness in the appraisal of a position, all this disturbs the logical development of a game of chess and enters into conflict with the diversity of form of a realistic art, in which living truth is reflected. (p.xxxv)
Whyld chapter in Winter (1981):
Smyslov's mature play is marked by sound positional judgement, powerful endgame technique, profound opening strategy, but relatively little emphasis on combination. (p.94)
Tal made a revealing analysis in a lecture, 'In this tournament [34th USSR Championship, 1966-67] Smyslov had a positional and strategical advantage in almost all of his games after 25 to 28 moves. Almost imperceptibly many of them became positionally lost a few moves later, and in the end he had only four wins in 20 games. When Smyslov reached the point of exploiting the advantage he had built up he could not avoid tactical continuations. For a long time he has been of thise players who do not like to involve themselves in the calculation of precise variations, and in this tournament this became particularly obvious.' (p.95)
Kasparov (2003) didn't give his own opinion, but he did repeat Botvinnik's:
In the period 1953-58 Smyslov was undoubtedly the strongest tournament fighter. His talent was universal -- he could play subtly in the opening, go totally onto the defensive, attack vigorously, or maneuver coolly. And this is to say nothing about the endgame -- here he was in his element. Sometimes he took decisions that were staggering in their depth. The combination of good calculation of variations, boldness, independence, and natural health made Smyslov invulnerable at that time. (p.381)
Kotov and Yudovich (1961):
Smyslov's chess talents lie first and foremost in he sphere of combinations. To complement them, he has extensively studied problems of strategy, technique, and endgame play. (p.140)
References expanded in V.V. Smyslov.