It’s much easier to list the good developers on the Marketplace than the bad ones… 70% of the stuff up there is shovelware or a cash-grab.
There’s nothing wrong with most of the Carenado stuff - just know what you’re getting. Top notch modeling and texturing, and a default flight model and default systems. That’s it. I wish they’d update their stuff more and take advantage of updates in the sim, but that’s been their MO for ages. 2 updates and done.
The Twin Otter is strange - it feels like it should be a good plane, but it just gets weird below 80kts on approach. I feel like the throttle response can’t be right - the real plane would be unflyable… beta range is super slow to go into and out of… makes water taxiing insanely hard. Aerosoft needs another update or two on this one. …and yeah - it’s loud af. 
There’s about 10 airport developers that make consistently good stuff, and I’d take a hard look at anyone else. ( Although even a couple of the top devs don’t seem to care about optimization and instead would rather make fully working interiors that you only look at once… but it takes 3x longer to load into their area, and you take a huge fps hit… and they seem to be fine with that. )
TLDR: check a few youtube reviews and make sure you know what you’re getting