With a machine like the HQSS / Tiara - there is much less need for spontaneous presser foot changes. There were only 2 feet available when I bought mine, they have since come out with the couching foot - and apparently an adapter which makes it possible to make the change more easily.
The closed toe foot is better for ruler work as you have a continuous round to butt up against the ruler. The open toe gives more visibility - similar to what you get on your domestic machine.
On a domestic sewing machine it would definitely be a huge issue to have to run to the dealer for every presser foot change as I may use two or three in a given evening.
Cheers, K