Thanks for sharing!
EDIT OCT 22: My HD 7970 went from 17 MH/s to 33 MH/s. I'll go back and revisit the R9 290 when I get some time

EDIT OCT 24: Can't seem to improve the hashrate on the R9 290

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Here on Linux (ubuntu 14.04) the slight edge goes to the original kernel. I tried it on both sgminer 5.1.0-dev and also on sgminer_v5.1_2015-03-09.
These are my AMD Radeon R9 290 original kernel results:
[22:55:20]
Summary of runtime statistics:
[22:55:20] Started at [2015-10-17 22:42:40]
[22:55:20] Runtime: 0 hrs : 10 mins : 50 secs
[22:55:20] Average hashrate: 27.8 Megahash/s
[22:55:20] Solved blocks: 0
[22:55:20] Best share difficulty: 12
[22:55:20] Share submissions: 230
[22:55:20] Accepted shares: 225
[22:55:20] Rejected shares: 5
[22:55:20] Accepted difficulty shares: 4
[22:55:20] Rejected difficulty shares: 0
[22:55:20] Reject ratio: 2.2%
[22:55:20] Hardware errors: 0
[22:55:20] Utility (accepted shares / min): 21.39/min
[22:55:20] Work Utility (diff1 shares solved / min): 0.40/min
[22:55:20] Stale submissions discarded due to new blocks: 0
[22:55:20] Unable to get work from server occasions: 0
[22:55:20] Work items generated locally: 1015
[22:55:20] Submitting work remotely delay occasions: 0
[22:55:20] New blocks detected on network: 31
These are your kernel results:
[23:06:19]
Summary of runtime statistics:
[23:06:19] Started at [2015-10-17 22:55:29]
[23:06:19] Runtime: 0 hrs : 10 mins : 40 secs
[23:06:19] Average hashrate: 27.5 Megahash/s
[23:06:19] Solved blocks: 0
[23:06:19] Best share difficulty: 5.232
[23:06:19] Share submissions: 207
[23:06:19] Accepted shares: 205
[23:06:19] Rejected shares: 2
[23:06:19] Accepted difficulty shares: 4
[23:06:19] Rejected difficulty shares: 0
[23:06:19] Reject ratio: 1.0%
[23:06:19] Hardware errors: 0
[23:06:19] Utility (accepted shares / min): 19.51/min
[23:06:19] Work Utility (diff1 shares solved / min): 0.36/min
[23:06:19] Stale submissions discarded due to new blocks: 1
[23:06:19] Unable to get work from server occasions: 2
[23:06:19] Work items generated locally: 962
[23:06:19] Submitting work remotely delay occasions: 0
[23:06:19] New blocks detected on network: 19