Me too - and it is perfect for the job! Not sure what D_W is so worried about.
First, addressing the dirty wood, etc. There's nothing about such wood that an old wooden plane won't work on (and better). I'm not sure why there's some thought that filthy wood requires a special oddball plane that costs more than a jack plane by some factor.
As far as "worried about"? I've been down this road. I do most of my work by hand, but to a standard. Not to a chippendale standard, but to accuracy that doesn't leave someone seeing the work as done by hand. I've been down this road, and had all of the planes mentioned here. The question at the beginning of the thread is how necessary is a scrub plane? The answer is, it's not necessary at all, and generally, it's a full step backwards to use vs. a jack properly set (not a jack length plane set up as a smoother or jointer). It is suddenly popular despite not much popularity in the past because of the market of beginners - in the stanley catalog, the scrub plane is not marketed with the bench plane, it's marketed with a bunch of goofy planes like furring planes, etc. It's a trinket.
re: the narrow iron, there's some idea that it can just penetrate deeper and make up for things, but if the corners of the iron get into the work, you're tearing wood rather than cutting it and wasting even more energy. If you resign yourself to the width of the iron, you're stuck with a fraction of it in practice and working less efficiently than a jack. To understand how much work it is to dig the corners of an iron into work to remove heavy work, one can easily do the same trying to push a chisel through wood with the corners buried. It also causes prying and tearing.
Is it something to get "worried about"? Well, only in as much as providing decent advice. Most of the folks who idealize hand woodworking will buy a few planes, try them, get a thrill and then rarely use them. If someone wants to play with two premium scrubs, and hunt down some old ones or convert rabbet planes or smoothers, that's play. Play is fine, this is a hobby.
If there's some attempt to twist the answer into a scrub plane having a productive role in a shop where it works better than a jack plane, it's just incorrect. It's also more expensive.
The answer to the original question is, the scrub plane isn't necessary. And unless the point is just to play, it's not even gainful unless you're a traveling carpenter with only enough room for a scrub plane and refusing to use a power planer attached to a vacuum (and that's a very unlikely thing these days).
I mentioned something about wooden jack planes being hard to find over here, and they are a little harder to find in good shape and of good quality, but the same day I said that, I found two english jack planes for $20 as a pair on etsy here. They were being sold to decorate, turn into lamps or use as door stops. Both were complete and would be fine to use.
I can't imagine converting a stanley 78 or any of this other something for nothing gimmick nonsense that paul sellers provides. That's his job, though - suspension of disbelief gimmickry under the guise of making woodworking accessible when it's already accessible - especially in England.
There are a couple of places here in the states that weren't settled by many and where not much wood grows - those places are referred to as "old tool ****" here. They may have a case about things having been hard to find before the days of ebay, but that's not the case now, either.
