Most vendors are basically the same. It takes years to develop a good strain. these guys mostly buy a clone of some popular plant and cross it with some inhouse genetics and call it some gorilla glue variant or whatever if a trademark is involved. They are bulk seed sellers. That doesn't mean they can't hve decent plants, but more than a few strains will be meh.
I'm sure you can find some good strains with RQS and any other brand. probability is what sets the better vendors apart. unfortunately, there's not central repository with reliable information. check out diaries, seedfinder etc... a lot of people think what they grow, no matter what it is, is amazing, though, lol.
the botique seed sellers aren't necessarily the best source either. It's more of a damned if you do, damned if you don't, lol. Those monkeys try to charge 20-30/seed or more far too often. If they do get popular they often go the bulk route and cash in on the name. Make a bunch of strains but maybe not putting in as much time as they used to developing them.
relies too much on word of mouth and if gossip is outdated you miss the boat.
price is not strongly correlated to quality. I'd just search far and wide and try more than one brand till you find something you can trust. I've been growing ethos the last couple years. I like them better than rqs, sweet seed, weedseedsexpress, seedsman, etc etc but if i saw a strain i absolutely wanted from those vendors i would not hesitate to try it out. I don't think ethos is significantly better but probably a bit better on average than the well-advertised seed sellers.
I'd like to try some humboldt seed company seeds, but not sure if i want to spend 140+s/h for 2 5 packs. That's fucking ridiculous given how cheap it is to produce seed. I like to keep it somewere near 10/seed or less, and i don't count 'freebies' in that math. YMMV. I want specific things not random, so the freebies don't carry as much value for me.