While we don't live in a split level, we have two set of friends that each live in a split level. Ones has the tri-level, the other bi-level. Heres the take on the two houses.
The tri-level. You go in the front door and you are in the living room. Kitchen, dining area, half bath, and laundry room are on this level. You can enter the garage thru the laundry room, which is off the kitchen. The living room and kitchen are open to each other, feels very spacious. When you walk from the front door towards the kitchen, the stairs are to the right, in the middle of the house. Ten stair up, ten down. They have 4 bedrooms and 2 full baths upstairs. Downstair, is a family room, storage area and half bath. The ceiling doesn't feel like it is sitting on top of your head. DH is 6'2" and he has plenty of room. Not sure what they did with the windows, the redid them not long after they moved in, but it isn't "dark" down there.
The bi-level. You go in the front door and you either go up or down stairs. There isn't much room once you get in the door. Once you go up the stairs, you turn and there is a very small landing and a long hall way. The landing, ie living room, can hold a small couch or a love seat and a chair, small coffee table. As you go down the hall way, the first door you hit is the entrance to the eat in kitchen. There is a sliding glass door that opens to a large balcony/patio and a set of out side stairs take you down to the yard. There is no other acess to the back yard area from this floor level. If you continue down the hall you find 3 bedrooms, 2 full, but very small bathrooms.
If you go down stairs, once you get to the bottom of them, there is a door to the right, which is the garage, a door in front of you, which is the storage area, or make a left and you are in a hall way. Go about 2 foot and there is a door way on the left which is the family room. Why there is a wall creating the hall way running the entire length of this lower level, who knows. It just makes the family room smaller and this level very "dark". The ceiling is very low, also helping the "dark" feeling. If you walk the hallway, you find 3 more rooms. One is a half bath, the other is a den/bedroom, and laundry room at the very end. There is a door leading to the back yard in the laundry room. The feel in this house is very closed in. Even though our house is smaller than this one, we do more at our house, then here.
When we were house shopping, we had looked at a bi-level, but just didn't like the flow. Spending time in our friends, confirmed that it isn't our style at all. Now the tri-level, I could live with that.