I'll answer this without question. 100% the full upgrade is worth every bit of it. Tons more power than the v4s and the app makes every a ton easier.
I'll admit I like the v4 color rendition better with more violet and uv but I've gotten used to the icons.
The upgrades literally replace all the internals minus the heatsink and lenses. So if you're handy, you could build new fixtures with the v4 parts...
Not sure if it's just the leds, the boards, or a combination but the icons produce a ton more power and par than the v4s. I used to run my v4s at 100% on my blues and uvs, now my blues are at 80% max and uvs at 65% and run around the same par.
So in a nutshell, if you're on the fence, do it!!!