To be fully precise, the exact extent of the revolutionary atrocities in Vendée and elsewhere is a matter of some controversy. Unfortunately, as it happens with all atrocities that become an issue in ideological battles, there has been both exaggeration and denial motivated by sympathies for one or another side. However, as far as I know, there is no serious disagreement among historians that the extent of atrocities was unparalleled by anything else in Europe that happened in the centuries between the end of the Thirty Years' War and the rise of the major 20th century totalitarians (i.e. Bolsheviks and Nazis).

(Again, if I'm missing some counterexample, I'd be really curious to hear it.)

To give another illustration, one way in which the French revolutionary regime clearly stands out is its really extreme bloodthirsty and exterminationist rhetoric, which is again unlike anything else seen in European history until the outbreak of extreme 20th century totalitarianism. (Some of this rhetoric is still reflected in the lyrics of the Marseillaise calling for the spilling of "impure blood.") When such rhetoric becomes mainstream, similar deeds usually also follow. (The advocates of "hate speech" restrictions actually have a point when they argue this, however much they tend to be confused or disingenuous otherwise.)

On the other hand, the fact about the European wars in the period 1648-1789 being limited, professional, disciplined, and reasonably considerate towards civilians is completely uncontroversial in mainstream history. The standard name for the type of war in this period is "cabinet wars" (German Kabinettskriege). The Wikipedia page gives a concise summary.