Just flashed 19484 for the wzr-hp-g300nh this morning - about 2 hrs ago, and from what i see, txpower adjusting does nothing to increase or decrease the txpower - it always stays @ TX Power 24.0 dBm (EIRP av.) / 29.3 dBm (Peak) in the status - no matter what you change to it, which according to inSSIDer isn't correct values, its not transmitting at 24 average or 29dBm. Not that the signal is bad or anything, but when you change the txpower value to something reasonable (17 thru 21dBm is reasonable for a consumer router), it should adjust accordingly.
Couple of other issues i am seeing as well, WPS is still included in these firmware releases (its not in community dd-wrt builds), WPS is insecure and very hackable, and simply turning it off in the firmware doesn't stop the hack according to some websites i have read on this subject.
Also, using a client mode + vap setup (Atheros repeater) the virtual interface is still reporting incorrect channel values within the webgui. The dmesg log still ends with the following errors:
<6>[ 1170.080000] br0: port 3(ath0.1) entered forwarding state
<6>[ 1170.080000] br0: port 3(ath0.1) entered forwarding state
<6>[ 1170.720000] br0: port 3(ath0.1) entered disabled state
Then ath0 tries to associate with the host AP, this is where the channel value for the VAP gets buggered, upon ath0's association with the host AP, it looses what channel it should be reporting for the virtual interface.
Atleast this build has a functional VAP, with the community 19519 dd-wrt build, any VAP setups appear to be non-functional, and this seem to be affecting not only client mode + vap configs, but WDS configs as well. This is affecting multiple Atheros units (tested on G300NH and AG300H) - if not all atheros units using dd-wrt. Bug ticket has already been filed to the community dd-wrt trac svn, but it would appear this is a low priority matter - and according to one of the devs, most likely will not get fixed this year. Time to roll back to 18024, atleast for me, most everything in it works minus the vap reporting incorrect channel values within the webgui. meh!