If you have no moral objection to magic racks (or accu-rack), then you should get one.
There's no question they keep the balls together better than any triangle. If the balls are not different sizes, then every single ball touches, easily, with almost no 'rack massaging' needed.
But, if you feel it's not right because the rack sometimes can't easily be removed from the table, and may affect the roll of a ball... then you must use a regular triangle. In that case, delta-13 is definitely the best. But yes, get the inserts to prevent the loud metal clanking.
If you still can't decide, the magic rack is a very cheap investment... 10 or 20 bucks. So you can try it and if you don't like it, you won't feel like you wasted a lot of money.