Wow, yall really jumped him on this one. And while i agree with many of the sentiments echoed, loading from the bottom (especially an sks) is super easy. I have never ever ever loaded my SKS from the top or with strippers. Hold the gun upside down with the muzzle slightly higher, tilt the gun to the side you need the first round on and fill er up. With an even round count, its easy to put the first round in where the follower is taller. It doesnt take any more practice really; just to be familiar woth your rifle, which you should be anyways.
But for a BDL style bolt gun, holding only 5 ish rounds, I doubt its much quicker. Though i find the follower and plate on a BDL bolt gun to be much more flimsy than the SKS versions