I've used mostly blackpowder but tried Pyrodex when it first came out in the '70's and have used a bit now and then ever since. I've heard all the horror stories about "wormhole" corrosion and such and can only say "I've never seen it". I've used it in roundball percussion muzzleloaders, percussion revolvers and ML pistols and shotguns, and in breechloading cartridge guns. In my experience with cartridges I've generally gotten better accuracy from Pyrodex than from black, probably because it fouls less and the fouling is softer, factors more noticeable in guns which are not swabbed between shots. Likewise I've gotten better accuracy with Pyrodex in cap & ball revolvers, probably for the same reason. In ML rifles I don't actually "swab between shots" but do use a wet lube, mostly spit, so in effect the bore is swabbed in loading and there I've seen no difference in accuracy between Pyrodex and BP.
Pyrodex IS harder to ignite. That is the very reason it was created, so that it could be classified as a Flammable Solid rather than and explosive like blackpowder. It is more prone to hangfires in guns which have marginal ignition,caused by a very small flash channel between nipple and powder chamber or which have a very small diameter powder chamber. Pyrodex RS has a very large granual size and simply will not flow into small diameter holes. An easy solution to that problem is to use Pyrodex "P", which is the same formula in smaller granules. That switch is very much like substituting 3f black for 2f black, reduce the charge a bit if it makes you uneasy.
I mostly shoot Goex black powder because I shoot flintlocks and Pyrodex is not much good for flint but in C&B revolvers, cartridges and percussion guns with good ignition properties I have no complaint with Pyrodex. Cleaning with water, drying and oiling after is no different than with BP.
Pyrodex no longer contains perchlorate, the formula was changed many years ago.