I had a look at the OXCNC website but didn't see any numbers for accuracy and repeatability.
Have you found any user reviews? I have found it is always a mistake to search for user feedback after parting with my hard earned.
Can the OXCNC be beefed up? The side rails seem to be enclosed by the gantry bearings, no room for added beef.
OTOH, if you aren't in a rush and do not mind whittling it away, beef is not necessarily necessary.
Is there a worry about dust getting in to those linear bearings? They are completely exposed and wiper free.
You pays your money, you takes your choice.