There is no data on the 525 yet. I'm speculating based on the 520. I don't expect the 525 to be much better.
Daylight visibility is something that is hardly mentioned in reviews. A few have started but its limited only to flagships. What about the rest. Not everybody wants to buy flagships. You don't get to test this out before you buy unless you know somebody that already has it. As the table shows there is still quite a variability here between models, phones are not yet standardised to the point where you don't need to consider it. Cheaper phones will cut corners or they won't be cheap.
Even then its very difficult to tell because it depends on the use & angle etc. Cloudy day not so cloudy. In a way we're lucky because we enter monsoons just when the sun is highest but its not a given. Too many variables to give a coherent answer.
somebody had asked this question earlier and no good answer was offered so i was looking for a way to gauge based on measurements with any phone or at least ones which have been measured. above average or closer to excellent and chances are it won't be a problem. I don't even need to own the phone as it's not anecdotal but based on measurements. Chances are better than even that owners will agree.
Same with battery endurance. Anything that's over 60+h endurance rating on gsmarena is a device that will not have issues with battery. There is quite some variability with lumias here. 720/1020 are good. 520/5, 620 are ok. 820, 920, 925? are average. If you can replace the battery its not a biggie.