yes, match the flooring for a unified look.

^Agreed - matching hardwood throughout a home is timeless

I put red oak in our house in August. Yes, it is still being used.

What finish do you recommend for the Red oak?

Our floors are light - no stain, just a water-based sealer (Bona intenseSeal) and 2 coats of Bona Traffic, with a UV cure.

It will cost less money if you continue the red oak into the bedrooms since you already have it in your family room and on your staircase. Also, red oak is less expensive than white oak.

European oak is very nice - I had it installed upstairs in the hallway + bedroom/closets. I thought about using it throughout the entire house - however, I didn't want the red oak that runs through my first level to be ripped up and thrown in a landfill. It seemed very wasteful - especially since it's solid wood and hadn't ever been refinished So, I decided to keep the red oak on the first floor - but used the prefinished European Oak upstairs.

I am going to refinish my red oak shortly. I have been "collecting" stain/finish options - I've seen some very pretty red oak floors

I would match if all on one floor. I have different flooring on my second story which has bedrooms but it is so nice to have one type of floor continuing throughout on the same level.

One benefit from using engineered hardwood is the visual beauty of wood grain structure in a wide plank. That's not available when using solid. An engineered plank with a 6mil top layer can be refinished several times. Solid can be refinished only until you approach the tongue and groove. Water clear matte poly and wide plank are the current standard in new construction.

IMO same floor material and same width too.

Match the existing. Red oak is timeless and beautiful.

738,00 new homes were reported sold in September, reflecting contracts signed in July. Find me a major builder or any builder of new homes using 3-1/2" solid red oak. Using that product would be commercial suicide. LVP is more likely.

D

R Horton uses lvp. Empty House Tour | New Construction Tour | The Galen built by DR Horton | DR Horton Homes (youtube.com)

Lennar Homes | Lennar Homes Concord Floorplan | New Construction Home Tour | Model Home Tour (youtube.com)

Maryland Home Tour | Longwood Model by NV Homes | Ellicott City, MD (youtube.com) You have floors. You're making a substantial investment to replace a large portion. Get current product for your effort.

Same thing in Japan, where new houses are actually affordable

【SUUMO】Miyama City's newly built detached house, condominium, house purchase information

15 million yen is 100k usd.