Yes, it will for sure.
For the best / highest TX power, you should have the card set to "default" this is usually almost always best, unless you are lowering the power below maximum card levels.
Your R52Hn power settings are normal, at least, they are the same as my R52Hn settings...
Note:
25Dbm is only specified for 802.11A and 802.11N (2Ghz) 6Mbit / MCS0 20MHZ Data rates.
There is a power offset, but i don't think it is an exact dB value.
You can view the specs on the card by downloading this file:
http://routerboard.com/pricelist/downlo ... ile_id=202