I am working COTA MotoGP/MotoAmerica this year in flagging/communications. Arrive on Wednesday night and full schedule Thurs-Sun but lot's of fun. Then I have most of the east coast MotoAmerica races set.
Being on track (well off to side of track) is definitely best seat in house.
To get the best experience of the racing (throughout the field), watch it on the screen.
But going to the track gives you an entirely different experience - the 'ambience' thing.
And finally ... there's no such thing as bad weather, only bad clothing!