We didn't stay at the El Tovar, but we did have lunch there when our train arrived in the canyon. The inside setting was beautiful - just what you would expect from a grand old hotel from the early 1900's. Not only have Teddy Roosevelt, President Bill Clinton and Sir Paul McCartney dined there, but children of the 80's will remember the exterior of the hotel from National Lampoon's Vacation. Ask for a window seat to fully enjoy the views.
The lunch dress code is more casual than the dinner one. We had on shorts & were not out of place. The meals were reasonably priced & quite good. I had a grilled veggie sandwich & it was fresh & prepared nicely. The bread basket is delicious as well.
If you can't afford to stay at the El Tovar, definitely make it a lunch stop. It is a true Grand Canyon experience!