Starter Clubs have a faster meter than Beginner Clubs. You'll notice that Starter Irons have 1.0/5.0 meter speed, while Beginner Irons have [roughly] .3/5.0 meter speed.
As you continue to upgprade your clubs to better equipment, you'll find faster meter speeds. It's simply something that you'll have to get used to, in all meter-based golf simulators.
Be thankful while the meter is so slow! The i15s meter is about 3x that fast.