Quality wise, are they all pretty decent or are there brands that are significant better than others?
Some are better than others. I have a 2x4 pre press, so I use 2x4.5 bags and fold over the extra material. Not everyone carries that size.
I found bags not sized as advertised (,low temp plates) and bad seams (Amazon).
The bigger mesh bags are nylon (I think) but the smaller mesh bags are like silk. So there are material differences.
I use 160 mesh mostly. And 25 micron mesh for kief and I repress dirty rosin in them.
In a session I might press 5-6 ounces at a time. On the second press, I up the temps ten or fifteen degrees and fold the puck in half.
On the second press I may get a little plant material in the rosin. If that happens rather than pick out every tiny piece, like I used to, I use a fine mesh bag and resqueeze the dirty rosin, using low temps and light pressure.