I liked it.
As a model building kid in 1977 and into the 80s, when the Colonial Viper came out, it looked too similar to the X-Wing fighter in terms of color, markings and overall design (long nose, single seat at the wing roots, multiple engines).
Monogram's Colonial Viper (the kit arrived before the TV show) was a superior kit to the original MPC X-Wing because Monogram made much better models than MPC back in the day.
But the X-Wing had better features of the day; opening canopy with pilot, removable R2 unit, opening wings, landing gear, etc.
Monogram's Viper had a solid canopy with a decal instead of glass, no gear and it shot a missile dart thing. Out of the four single seat fighters, Viper, Raider, Vader's TIE and X-Wing, Vader's TIE was the superior representation of vehicle. It was also more in scale with the Viper and Vader did best my Viper in multiple space battles!