Sorry, I never watched enough StarGate to know about their replicators. How are theirs worse than Star Trek's?
Stargate's replicators were what Star Trek's Borg always should have been; an implacable, unreasonable, single-minded enemy that acted like insects (and actually looked like them too,) adapted to threats, and even gave the most powerful civilization around (the Asgard) a lot of trouble.
When they finally did introduce their variation of the "Borg Queen" (human form replicators with individual personalities) it wasn't Star Trek's weird "hey, we know we said they were a hive mind with no central authority... but we want a Queen, so RETCON!" It was an actual evolution of the "species" after a particularly misguided attempt to wipe out the replicators went horribly wrong and locked them in a time dilatation long enough for their AI to continue to grow and become self-aware.

Also: THEY LOOKED LIKE A LEGO PROJECT FROM HELL!!!

Each of the "blocks" that make up this insect are actually individual Replicators. They're basically tiny super computers with one goal: consume resources and replicate (the story behind their creation is dealt with through various episodes.) In order to fulfill their goal, they combine in various ways to defend themselves and more easily consume anything in their path. The insect form is the most common variation.
And since the main character of Stargate is played by Richard Dean Anderson, the show basically turns into "MacGyver vs. Lego Spiders" and it is awesome.