Using the Z kernel I just broke 900 khash/s with a water cooled 780 TI. This kernel ended up being 11% faster than the 12-18 releases T kernel. I had to use -H 1 for the extra 8 hashes over -H 2, at the cost of 25w. A terrible trade, but it put me over 900.
N-factor 9 Microcoin is running at @ 834 khash/s. That's a much smaller loss than a R9 290 takes. They are now yielding 666 vs 880 on scrypt. The memory overclock actually helps on Microcoin, but it isn't an efficient trade. 8~ hashes for 8~ watts. Also, solo mining MRC was terrible for me in the few hours I tried it. I had several times better results in the blocksolved pool.
http://i.imgur.com/BEONlhE.jpg