Hmmm as my normal descent on finals would be about 400 ft/min then 1,700 ft/ min sounds a lot.
I make it (1700 / 60) x (60 / 88) = 19.3 mph. suppose its a good bit slower than without the parachute but it still seems a tad quick to me. That's why I've never had the urge to leap out of a serviceable aeroplane.