Or you can do the math yourself. There will be ratios with your present gearing that are similar to those you'd have with a compact. Figure out what they are and take a ride using those gears. Formula is the number of teeth on the chainring divided by the number of teeth on the rear cog, multiplied by the wheel diameter (27 for 700 wheels, 26 for mountain bikes). Result is in "gear inches," a standard measure.