Tons of people who actually have this model are about to opine but I have 4 tanks on 2.0'a and can give you my 2 cents. As far as I understand, and I may be corrected, the 3.0 is more timed and computerized than it is more lumens output. So having tinkered with the 2.0 lights for a several years now, they grow plants. They are pretty darn great.
Nothing good happens fast in an ecosystem.