Hey David,
I understand very well that one has budgetary limits but one also has requirements for what one wants to accomplish. The Ratrig machine may be cheaper than the Onefinity depending on configuration, but you get less for it. It uses lead screws and not ball screws. I would not choose such a machine just for the 4′×4′ workarea (instead of the 4′×2.7′ workarea of Onefinity Journeyman) especially not if there is hope that there will be 4′ Y on Onefinity sooner or later. I also agree to what Bill said here.
The Journeyman stepper is NEMA 23 and high torque in stock configuration. And even retrofitting bigger steppers is not expensive because these are all open-loop (“step-and-pray”).
Then obviously you really have to look at the money. This is the cheapest type of milling motor possible, a hand trim router which isn’t even allowed by its manufacturer for use in a stationary machine.
One advantage of the Ratrig, like the cnc-step High-Z, would be that they offer a 43 mm mount which opens access to a wide variety of single-phase, universal (non-VFD) professional milling motors like Kress, Suhner, Mafell, etc. This is something the Onefinity manufacturers don’t offer (who knows why). In contrast to your hand trim router like Makita RT0701C, such milling motors are allowed and made for permanent use in a CNC and they are delivered after run-in by manufacturer, like spindles are, but unlike spindles they don’t need a VFD and an electrician to install them.
If I hadn’t already had the Journeyman delivered, what I would have done in your place is to ask info@onefinitycnc.com directly if or when they will make a Y-50 48″ machine or upgrade available.
Regarding the Buildbotics Controller, besides improvements here and here, you have a nice display that shows relevant information e.g. it indicates the assigned IP address, and you have a 15-pin auxiliary port for the use of external motor driver modules which adds to versatility. The Buildbotics controller also looks good at the Onefinity 
.