Stargate SG-1’s First Blu-ray Brings Improvements … With Some Flaws
This is a meta-review by top fan site GateWorld. They don't have the discs, they link to five sources and summarize.
Basically all but last three season are upscaled DVD. The last three in HD are not as good as streaming. Completely botched the 5.1 audio from DVD.
https://www.gateworld.net/news/2021/01/stargate-sg1-first-blu-ray-brings-improvements-some-flaws/
https://www.blu-ray.com/movies/Stargate-SG-1-The-Complete-Series-Blu-ray/282609/
FYI (Imdb):
Seasons 1-3 shot 16mm; 4-7 35mm. Both edited SD video. seasons 8-10 HDCAM.
16:9 HD (original broadcast ratio) (seasons 6-10)
4:3 (original broadcast ratio) (seasons 1-5)