I run a Taig personally and love it, but I make REALLY tiny parts. The Taig is actually the giant of my three machines.
Just my 2 cents, but I would really lean toward the X3 for any "real" machining.
The Mach controllers initial setup is no big deal for any machine, especially one as popular as the X3.
For the CAM program, any CAM design program is pretty standalone, whether it comes bundled or sold separately. It is usually the same unaltered generic program you would buy elsewhere, at best there may just be a price break given. There really shouldn't be a lot of weight placed on whether or not it is part of a package. Integration just isn't a problem.
In general the CAM output, regardless of the machine you have, is only tailored for Mach anyway. Only Mach needs to be setup to handle translating based on the specifics of the given machine - I generate the same G-code from my CAM programs regardless of which program I use that day, and regardless of which my three different machines it eventually goes out to - the CAM's just all write in generic Mach, and Mach is just setup with three translation profiles for me to choose from.
In short, buy the machine you will best use and need based on its performance alone. Any "package" advantage for the software is fleeting at best and might only save you an hour or two of initial setup at most.