You know Dave I have never tried to speed load my FAB-10. My 20" upper I just leasurely load for shooting squirrels and I still haven't got around to buying a bunch of cheap FMJ to shoot through my 11.5/5.5 upper. I have found that adapter for the stripper clips isn't the greatest design. Also, I don't know if this is specific to my FAB-10, but my gun will only hold 9 rounds in the magazine. Why? 10 rounds will fit in the magazine, but the fit is so tight, when you close the gun back up and try to pull the charging handle, it won't budge because the bullets won't come down from the bolt to allow the bolt to move to the rear.
In theory this shouldn't be too much slower than loading up your SKS with strippers. The only disadvantage is the SKS has its stripper charger as an integral part of the firearm and the FAB-10 has a bulky attachment that you are going to have to tote around with you and not lose. The FAB-10 does have the advantage of being able to top off as the SKS won't single load until you are out. Both systems are at a disadvantage from the shotgun that can be loaded with a round in the chamber and if a threat presents itself you can still shoot quickly.
For toting the FAB-10 around all day on a coyote or squirrel hunt, it works good though. Simply open the gun up and then place the buttstock inside your right armpit and apply arm pressure to securely hold the gun. Take your right hand and place it over the ejection port. Using your left hand, pull up on the bolt carrier by sticking a finger in the rear of it. The bolt easily comes up and the round will cant .45 degrees or so out. After the round passes by your hand, lower the bolt back down and grab the cartridge. Double check to make sure your chamber is indeed empty, and then fill up your magazine (to only 9!) and close the gun back up. Double check the rifle is empty by pulling the charging handle back a half inch or so and then dry fire. Now you could hypothetically carry the rifle around in your car with an empty chamber and a loaded magazine, just in case you saw a coyote on a "drive by" and wanted to roll down the window/jump out, charge, and shoot. However, it is illegal to drive around with ammunitition in the magazine or discharge your firearm from inside the vehicle and I would never suggest you do so.