Lenin and Stalin were equally ruthless in their use of terror - how far do you agree with this statement?

On the surface, Lenin and Stalin were equally ruthless in their use terror. However, by virtue of the length and intensity of Stalin's communist state, the very culture of Russia changes to one of permanent fear and submission to Stalin's will. As such, it was Stalin's leadership that was considerably more ruthless.
Historians have deemed Lenin's use of terror during the civil wars as excessively cruel, the Cheka established in 1917 overseeing the arrest of and execution of over 500,000 political prisoners. Stories spread of White army soldiers being disemboweled and tied to posts using their intestines, all under Lenin's orders. Lenin's Cheka gained such a poor reputation that they were disbanded in 1922. This was paralleled by Stalin's NKVD, who oversaw the imprisonment of millions of political prisoners in the gulags. Similarly, Stalin rebranded the NKVD into the MGB under Lavrenty Beria. Seemingly, both Lenin and Stalin were equally ruthless in the use of terror.
However, Lenin was able to justify his ruthlessness as pivotal to the establishment of a Socialist utopia. The white army were class enemies, and their predominantly aristocratic membership helped to justify the cruelty shown towards them. Over 2 million 'former people' were purged under Lenin, many fleeing to the USA as political exiles. Lenin's ruthlessness was a matter of political expediency. In contrast, Stalin's motives were far more sinister. His assassination of Kirov in 1934, Zinoviev and Kamenev in 1936 and Trotsky in 1941 suggested that Stalin was a megalomaniac who (unlike Lenin) had no qualms about killing a fellow Bolshevik. Whilst Lenin's ruthlessness was calculated and logical, Stalin's was indiscriminate, and this is what made Stalin the more ruthless of the two.