Know what you mean about Strawberry. Haven't found a decent strawberry concentrate yet and I'm running out of vendors to try.
NF strawberry.
I have been at DIY for a little over a year now; have made vast, vast improvements in that time. There are so many variables though! For one, being that I am not currently mixing for the purpose of sale, I mostly focus on things that I like - bakery & florals. My florals (if I may say) are better than those of any vendor I have tried. A couple of my sweet/bakery flavors will match many vendors. The largest improvement I have noticed in the past year is a marked improvement in initial guesswork; that is, I can predict at what strength a flavoring will be good, and which flavorings will work well together... to a reasonable degree. I can sit down with base and a collection of flavorings & in a short time produce a few flavors that will be vapable, perhaps even daily vape good, though it is unlikely that any will match vendor products.
I often sample vendor juices at the monthly vapemoot, often come home with freebies, samples, and winnings. Vendors vary, there is a niche structure as with anything - some specialize in tobaccos, or fruits, some make ridiculously good flavors of any kind and charge you accordingly... some make mediocre flavors and sell them cheap. I can DIY juice that is as good or better than perhaps 50% of vendor flavors. Some things I will never be able to DIY: highbrow RY4, TVR toasted tobacco, vapealicious goddess... maybe they use specialty ingredients, maybe they have tweaked over years with thousands of samples, idk. Vendors do this for a living. They test hundreds and hundreds of flavorings; they make and test thousands of samples to arrive at a single perfected vape. I EXPECT them to be better.
I vape 95% DIY. The vendor juices I load up come from vapemoots and cons. DIY is so much cheaper, and provides a hobby to boot. To be honest, being both poor and stingy if I did buy juice it would be from low-end vendors, whose juice is on par with my DIY mixes and still much more expensive than them in the long run.