It depends on your needs. If you already own class A preamps, converters etc, then no, I don't recommend it. However...
As a nucleus owner I can tell you that it is a great piece of gear. I got rid of all my mediocre stuff and replaced them with just this one unit. I use all of its features; the preamps, the usb soundcard, the monitor section, and of course the MCU/HUI controller.
Great faders, great build quality (compared to Avid artist and Mackie) great pres, converters, analog section. Very pleased overall. I just can't go back to working with a mouse and keyboard. The fully customizable buttons for USB comands are a very useful, time-saving feature.
For me, an ITB producer/mixer, who records vocals and not much else in a small mixing suite, it's a perfect fit, for others, maybe not so much. as always, YMMV.