Linking a WoL from a person and saying this is what he got doesnt realy help.
As it realy depends on the playstyle.if you raid heal pretty much 100% and just beacon the tank to help the tank healer, then Blessed life will come up trumps.
If your tank healing then Tower of Radiance should get better.
Personally i spec into both, and drop sacred cleansing and only have a 20 yard range on judgement as a loss for it.
As on herioc modes ive found tower of radiance ot be very beneficial to make my mana last just a tony bit longer, espcially on fights like halfus where sometimes you have to heal your beacon becuse he is taking just That much extra damage.
Or for example During feud, You can drop some big heals on the tank tanking during feud as he must stay topped, espcially once break stacks up. thus allowing more light of dawns to heal the raid.
Also some fights have more aoe mechanics, eg, chimareon drops slimes on 20% of ur raid group every 5 seconds, and the slimes during feud are every 10 seconds thus guarenteeing and extra holy power 3 times during it. Whihc is great seeing how thats the part where you want it for more LoD's