On the whole balance question, to make the UU cost per output the same as regular solars, you can make the output [Day (Night)] 6 (1) 20 (4) 128 (16). If you instead set it to hard build mode, you should boost the Advanced by 1N, and the Hybrid/Ultimate by 9N to compensate for the use of (non-renewable (except with extra bees)) uranium.
I just crunched the numbers, and thought other people might be interested to know how they compare, approximately.