Well, IMO each flavorist has good flavors and not-so-good ones. A lot like
juice vendors; the answer is dependent on what specific flavor you want, not vendors themselves. You asked a good example there: "who makes the best honeydew", or, even better "what kinds of honeydew flavoring are available?"
Flavor West is supposed to be easy to mix & good for beginners. Most any of their flavorings will result in something vapable and can be reliably mixed at 15%. I love many FW flavors, especially tobaccos. I have heard similar claims about capellas.
TFA is anybody's guess: each flavor requires different percentages, they have a ton of flavorings of varying quality & taste. Some people despise TFA entirely. Some love them exclusively. I notice more disagreement & confusion about this company than any of the others. I use quite a few from TFA.
Flavour Art is considered higher quality, and is usually a bit more expensive. They have many flavors, though not all of them actually taste good in e-
juice. They make quite a few exotic or unique flavors, and they offer many extracts/add-ons that are not for flavoring per se but for tweaking mixes.
Nature's Flavors is... ok, if you are a beginner just stay away from them. I love NF but they are very hit-or-miss, are alcohol-based and thus a PitA to work with, and they are constantly steeped (har!) in controversy.
There are plenty of other flavorists but these are the ones I have experience with.
My advice to a new DIYer would be to pick a couple end-juices you want to vape, concentrate on researching the small sets of flavors that would go into these, go to a place like
OneStop which sells flavoring from multiple sources, and work within the small set of flavorings. F.e. you want to make a caramel apple juice, so read up on caramel & apple flavorings, sweetener, maybe a couple other things that could go into that recipe: brown sugar, almond... idk, you get the idea. You will notice there are apple, green apple, apple candy, apple cider; caramel, caramel cream, caramel candy...etc. Probably a couple straight caramel apple flavorings too. Buy a couple apple flavorings, a couple caramels...etc and mix away.
The research curve for in-depth DIY 'mixology' is huge, but worth it if you want a new hobby.