I just looked at the two machines, yours (or at least the current offerings from i2r) and the Cue Demon. From a 500ft view, they are the same machine.
From a few details:
Your machine uses profile linear rails, the cue demon uses round rails. Huge advantage to your machine.
Your machine has an actual steel bed, the cue demon appears to be set up on a piece of plywood that you supply (?). Gigantic advantage to your machine.
The i2r has a better aspect ration of the x-axis car span and the z height. Huge advantage to your machine.
The cue demon claims repeatability of 3 ten-thousandths. I call BS.
Neither of these machines are really 'cue building' machines. Neither of these machines will ever drill and bore for a pin, or a-joint. You are right that the ir2 will take a bunch of modifications, but so will the cue demon. The biggest modification will be to also buy a lathe.
I don't understand what you hope to gain going from one gantry style mill to another very similar gantry style mill.
My advice is: If you are going to lose money on the i2r and then buy a cheaper machine, take the money you are going to lose and invest in tooling and education for the machine you already have.
If you feel like reaching out, give me a pm and we can discuss offline via pm, email, or phone.