I think the EconoJet/EconoMax/EnerJet single-use motors by Aerotech that are sold in 2-packs are a relatively good deal. I fly a lot of them at low-power launches.
Supposedly Aerotech is going through some kind of rebranding process, and all those sub-brands I mentioned above are going to be consolidated under one label: EnerJet.
Branding is not a strength of Aerotech, and they seem to like to throw in a few exceptions to their rules to undercut their branding concepts. So, the “Econo“ in the original names was originally meant to suggest a good deal, and one of the reasons for that is that they were made to have a maximum propellant weight that was under the hazmat limit, so you didn’t have to pay for hazmat shipping.
That’s what makes a motor like the F23 a much better deal than an F25 if you have to order them and have them shipped — the base price for the F23 is less, plus you don’t pay hazmat like you do with an F25. Of course, Aerotech just could not help themselves and released the G74, which DOES require hazmat, undercutting the logic of the Econo branding, so maybe that’s why they are rebranding and removing “Econo” from the name. Who knows?
These motors are great if you want to put up a lot of rockets in a row and not break the bank. It‘s true you can eventually break even and save money if you buy hardware and go to reloads, but you are probably still going to want some single-use motors, because it takes time to build a motor. I’d rather spend my time at the field flying than building motors.
The one complaint I have with the Econo motors is that they have started packaging these motors with crappy igniters. I hate ignition failures at club launches, because it takes so much time to get through all the other rockets and back to my rocket for the recycle. It costs me a flight for the day, and that pisses me off. So often I will just buy upgraded igniters, which are not cheap. That cuts into the value of the savings on the motors, but sometimes time is more valuable than money. If you are just doing your own park flying, it’s not as much of an issue as it is when flying with a club.
My favorite of these kinds of motors is the F20 — nice, powerful initial thrust to get things moving, and then a few seconds of sustaining thrust, plus plenty of flame, white smoke, and roar. The F67 and G74 are similar, but faster. In 24mm, the E20 is more like the F20, and the F44 is more like the F67. I like all of those. I also like the F23 when I want black smoke and the F27 when I want red. Personally, I’m not a big fan of the blue thunder type propellant options in the F42 and the E30 (I think).