Size of buds is relevant to the strain you're running, feed, grow method, too many variables. I don't grow by size of buds, I grow for a hobby and quality meds in soil with some supplemental feeding, running same strains in hydro would probably produce bigger buds but I'm not interested in that. I don't know if that 630 is equivalent to 1000 hps, haven't done a side by side which would be the only way to know. Just offering what I've seen/experienced and they are much more efficient and watt for watt they beat the shit out of hps, I setup my son to replace his hps watt for watt and he's producing ~25% more on average depending on strain with the same wattage he was running under hps, that's all I know first hand.