Not nowadays as the formula has changed substantially.
Flag's equivalent was a very good alternative until recently, but Toolstation/Wickes have stopped selling it, and it's hard to find (unless you want a pallet-full!).
I have tried the new eco-friendly Hammerite formula. Utter pants compared to the original. It may last better if you waste ages prepping the surface (cleaning, degreasing, marinading, whatever), but the point was rather that you didn't need to do that (as Sunnybob implied).
I still have half of a 20-year-old tin of smooth black, which is still fine after a top-up of xylene occasionally...
Which is better, doing the job once with the original, or four times with the new rubbish, and having to weld up rust damage too?
You might try Galvafroid followed by a simple outdoor gloss. You can matt it with white spirit, if it hasn't quite gone off completely, and Galvafroid really works although it is pricey.