If they harmed the tree much, I have a couple of Oaks that would be goners. The biggest problem was trying to get guests to believe me that there was a small grub inside. They all wanted to tear off a leaf and see. Those poor small trees could have been defoliated.

Sorta on topic: IMO you should plan for 100 years or so out of your residence. Sure some homes in the city are older but most are in ridiculously bad shape or have been rehabbed extensively. My home was one of the first siding and wood subdivision rectangles. It is 67 years old and doing ok. Many others in the area are slightly newer but not quite right due to human neglect though. Another thirty years and its empty lot near derelict home time. And yeah, I know with maintenance homes can last longer. My neighbor helped rebuild this plantation home across the street. IMO if it was not a commercial venture it would have been time to let it fall. Amazing the problems in the nicest of homes from 1850.

leaf damage on a deciduous tree.. is never a problem in my garden ... i would say.. 99.9% of that leaf is functioning just fine ... and surely not worth any remedy that can be dreamed up .. by anyone but a seller of said remedy ... individual cell failure.. could be as simple as a cold event just after leafing out ... but not knowing where you are.. who knows ... i dont know how you come to the conclusion its an INFECTION .. nor how dax can jump to nutritional deficiency .... he says he sees it all the time.. so the next logical step is that every tree he has seen this on.. has soil issues ... thats a bit far to reach .... unless this tree is in IL ... within his range of observation ... i agree with toms in depth answer.. 100% ... lol .. when every leaf falls off the tree in mid summer.. is when you start worrying ... BUT!!! .... if you are just questing for knowledge.. two thumbs up.. just dont freak about it ... ken

They are probably referring to the same thing. If you are in the Midwest most people will say Red Oak but if you look at a Quercus rubra tag in the nursery the common name will be listed as Northern Red Oak. In my experience Red Oak (or NRO) is quite variable in fall color but usually gives a decent display. I prefer many of the white oak hybrids like Prairie Stature, Forest Knight, etc... as they are more resistant to oak wilt and still give a nice color display in the fall. Growth rate of the red oak group as a whole is typically quicker than that of the white oak group. If your soil is acidic enough also think about trying Quercus ellipsoidalis or Quercus coccinea, both of which tend to have excellent fall color.