medicus 7 iron or medicus 5 iron? which would be more helpful and useful.
In my honest opinion, it doesn't really matter. When using a swing trainer, your not really focusing on the loft or distance of the ball. Medicus irons are mainly used to teach your muscles the correct way to swing so that it becomes almost second nature when you're using real irons. This is achieved by repitition. If you continue just to practice the correct swing, then you will greatly improve your shot. Aside from feet placement, an iron swing is an iron swing for most golfers. Buy whichever one you want, practice until it feels right, and you'll be hitting both your 5-iron and 7-iron better no matter which medicus iron you buy.
As the guy above me said, it doesn't matter. But just think what club you hit more often on the course, a 5 iron or a 7 iron, which ever one use use more, buy that one.