Re: Solas Amita vs Solas Rubex
No, IMO you're missing nothing. Reasons people usually give for buying interchangable hubs:
1. You can buy housings in 2 or 3 different pitches, and use the same hub to swap between them. Many disillusioned people think they can easily swap housings on the water if they hit something (more on this later). And other disillusioned people think this is cheaper than just buying 2 or 3 fixed hub props....this varies by brand...but often times it does not save one red penny, and other times can even cost more...as you have just found...
2. If you "spin" a hub, it is cheaper and a bit more convenient to usually buy a new replacement hub, than it is ot pay to have a prop "re-hubbed" at a prop shop. This is often true, by about $30 to $50 maybe?
In my mind, these "benefits" do not outweight the disadvantages of interchangeable hubs:
1. Those who have them, have you ever actually tried swapping housings on the lake? In few cases this can be accomplished, but in my experience, MANY times the hub gets stuck in the housing, essentially rendering it a fixed hub prop anyway. And if you don't have a press, or the proper blocks of wood and a 3 pound sledgehammer on board with you to bang the pieces apart, there is no way in heck you're changing housings during the day while on the water, despite your best intentions when you purchased the extra 1 to 3 housings for that "not-so-easily-interchangeable" hub prop. So you're stuck with whatever the hub is stuck inside of, or worse yet, left stranded...because your "spare prop" is sitting there on your boat hubless. And if you only have one hub for all your housings, what happens when you DO spin a hub on the water? Again stranded.
2. Price. As you stated, fixed hub props are often a bit cheaper. But this does vary by brand.
3. If you manage to "spin" a hub, it's because you hit something pretty dang hard. So if/when that happens you're looking at paying for a new hub AND a new housing anyway...or at least paying for a prop shop to repair your damaged housing, plus buying a new hub.
I purchased interchangeable hub setup...twice actually. First was Hustler. It was pretty much a PITA to change housings, even at home in the shop. And if I was out on the lake? LOL. NOT happenin'. And then for my next boat I bought a Rubex setup. Thankfully I've never had to change the hub out...as it's pretty well stuck in there also! Recently took it to a prop shop for a mild repitch and repair, and after briefly trying to push it out of there, I just decided to leave the hub in place while they worked on it. Pretty sure I couldn't swap that one on board either if given the opportunity.
So never again, and now I am very much a fixed hub guy, and I find interchangeable hub setups to be nothing but a marketing gimmick. I keep a full fixed hub prop installed on the boat, and another full fixed hub spare prop in a storage compartment, along with new nut/washer/cotter pin setup in case one falls in the lake...and obviously the tools needed to change it out.
If I were in your shoes choosing between Rubex and Amita, I'd go Amita hands down. In fact I am actually a current owner of both...and I honestly see absolutely ZERO benefit to the Rubex setup and I'm a bit sorry I paid extra and purchased it back when I was one of those disillusioned people I referred to above. The good news is that my Rubex does perform well, and having been mated together for a couple years it is now essentially a fixed prop anyway LOL. And when I decided to buy another pitch in the same design, I bypassed Rubex and just purchased another entire fixed hub Solas...because it was cheaper...and because it came with a built-in spare hub....and because the blade design was exactly the same...
As you have stated, the props and designs between the two Solas products are positively identical, and I have confirmed this to be true by talking on the phone about that very topic with a Solas product rep last year.