Then attention mod
Does not offer past mod versions and updates with every new part to rack up download numbers.
The pageant or balanced mod
Virtually offers nothing new other than good looking sprites and slightly different values for existing stats.
The meta mod
Goes with the waves of perceived meta type of parts e.g. bubble shield and roof turrets and has them in all colors of the rainbow.
The advanced or innovative mod
With every new type of parts it offers new functionality or mechanics at the time of introduction. Its coding is mostly updated with the latest game features.
The diehard mod
Offers past version of the mod, hence, support of most game versions. It is kept updated to the latest game version in reasonable time.