This are my two cents.
I pull the trigger and order one for my WB 190.5 after trying to get a hand on a Trident for months now with no success. Yes my tank is fully Apex control, besides the texting. At first I was hesitating because of the price point overall, including the monthly payment.
But in my personal case I believe that lots of us, we throw out heavy bucks on texting equipment and products we have to measure our self. And at the end sometimes we don't test as recommended because we all have lives besides our tanks.
I'm an Army retired veteran, "oh well... he got a pension he might have spear cash to throw away" you might say!!! Actually, I live with a monthly payment as everyone else with a lot of monthly expenses like everyone else. So no, I don't have that kind of luck. Beside I suffer from PTSD that sometimes I don't feel like doing anything. But my tank has been a life changer for me. And I have invested some money in and time as well.
Also I retook my music hobby to a next level where I road out from time to time. Leaving me out of monitoring the system, and coming back with some sort of problems with the water parameters, even that my wife try to do the best she can to keep it up while I'm away.
I place everything that I mentioned above in a well calibrated balance and came with my own and personal opinion.
The other monitors out there have their own cost themselves, and just give you not even a third of what MS monitor for you. For just few bucks more, but with much more data points and parameters in a easy and reliable way without to much effort from you.
That we have to pay for using it? Well, it's just how you analyze the situation. They send you the disc's on monthly basis for keep it up and running ( you don't have to be on long waiting lists for your reagents at least by now on those other devices) and an interface that you can access anywhere in the world.
Did they don't have yet a doser to be controlled by the device? I personally don't mind, because I have Apex Fusion and I will be able to make the adjustments needed if necessary to my DOS to keep it up.
While waiting for some kind of testing automatication I have wasted several bucks on expensive life stock(corals) while away. If I might say with all these losses it already pay it self.
So now it's just the monthly budget. As above stated it's just how you justify your investment. Not everyone is willing to pay a subscription and it's understandable. But, remember that sometimes we throw away money on other things that at the end was a waste of money and we regretted.
For me... I will be doing some budget adjustments in order to keep my hobby running with less stress. Instead of buying 4 cases of beers for the month I could pass by with 2 and a bottle of Whiskey or Rum. Buajajaja!!!
To close my point...
It's all about personal opinion and preferences. Some will not find how to justify the investment and other does. Some have the spare change and don't mind to pull the trigger just to have the latest gadget out there and other like me will have to make some adjustments to find a peace of mind on a plug and play gadget to monitor their systems.