I've got two X72s and one X12 plus three PEQ503 EQs. All sound quite fantastic! As compared with Neve 1073s the X72 have all the bottom end as the Neves but are not as veiled. The X72s have clearer sonic path through the whole spectrum, very much in the same family without the muddiness and cloudy veil as the Neves. The X72s plus the PEQ503 on bass drum has the punchy bottom end you'd expect as well as a very musical and tall headroom. I definitely prefer this combo over the Neve. Great on FTs, bass certain vocals, guitar and keyboards.
The X12 is very much like the API312, but has a smoother and not as hyped top end. Classically mid forward, which you'd want for certain sources. The X12 plus PEQ503 on snare is a marriage made in heaven. It's so smooth, open and has the explosive crack on the snare when you need it. Very much like a Tonelux, meaning it's what API should have built at, and of course the classic mid forward presence. Great on vox, guitars, OHs, keyboards, rack toms.
Yes, I would get a lot more of these units, plus the SC501 and XM5mk500 pres and a slew of PEQ503s. I love them, the build quality is excellent, bang for the buck is superb and the support is fantastic.