I started with the idea of F-series with a 600w driver. Instead of building a 4x4 light, I built a 2x4 light from vestas, and aimed at making it as flexible as possible. Eventually I will build the other 2x4 light, and it might as well run with one larger driver, and be fixed at an optimal color temperature for flowering.
What made me decide on the vestas had a reactive component (digikey didn't have EB2s), and on F-series I always found myself compromising on build designs to maximize the bulk discount (so looking at larger numbers of shorter strips). Finally looking at the F-series always had me feeling I should design the system to reach very high lumen per watt levels, since they don't shine when comparing lumens per $.
But there was also a constructive element to my decision. While planning the light and ordering parts I was doing a pheno hunt. I didn't' grow inside for over 13y, and thats where it begins. In my pheno hunt I tested the specimens with a mercury vapor metal halide (from the 90's), and with 2 different HID's with different color temperature bulbs, and a sulfur plasma. Naturally node distance was not the only variable that the lights were causing, but as expected the effects were quite chaotic. Even within the same strain it was obvious that a perfect color temperature for veg varied for each specimen. Also the degree that spectrum affected strains varied a lot too. My initial conclusion is that if I was designing a commercial op (I'm certainly not), I would design each room around a specific clone. Since I have no idea on the strains the future has in mind for me, I opted for flexibility, and a lamp that allows me to adjust and learn from the strains I am working with.
So my vesta top light has 9 strips with 225w on 2700k, and 225w on 5000k. There are 3 drivers per color temperature, so in veg I can just light 3 strips @75w (or 150w) or 6 strips @ 150w (or 300w). If I'm growing stretchy strains I can veg with 5000k, and if I'm growing some slow indica I can veg at 2700k. I can even veg @ different color temperatures at the same time. The way I see it is i'm not optimizing money per watt, but my potential for learning. I have been thinking about building the other 2x4 light with 80cri so I would have the option to compare that too.
I read a bunch of comparisons between 80 and 90 cri, and for the moment it seems a little confusing. Some people got amazing results from the 90cri, some didn't. Some said it speeded flowering, others said they got more crop per days flowering with the slower 80cri. One area 90cri seems to rock at is in lower levels of light. Waiting to see comparisons for clones, sprouts and early veg.
Certainly if someone knows they don't need color temperatures over 2700k then Vestas loose a lot of appeal. Also in bigger builds the F-series bulk discounts start to become quite meaningful. Unfortunately by the time conclusive evidence and experience with mid level leds builds up, market offerings will have likely already changed. I think in a year all the products we discuss will have already changed
One last point that affected my decision was my plans of making an indoor vegetable garden for my mother. The adjustable spectrum will really be important there. I imagine within 2y my vestas will have found a permanent home growing salads, herbs, tomatoes and cucumbers for my parents. Also I can defiantly recycle them into home lighting.
