If you find yourself stuck between sizes, try using different tape builds to change the sizing. You can get an in-between feel by adding wraps of tape to increase the size slightly. One wrap will increase grip size by 1/64, two wraps 1/32, four wraps 1/16, etc. Note that 2 wraps would get you the most in-the-middle sizing between 2 sizes (i.e adding 2-3 wraps to a standard size gets you midway to a midsize).