Lunchboxes are popular among the set that think you need a dozen flavors of everything. If you are happy with a couple of nice pieces, it will be cheaper to buy regular rackmount boxes. This is because there are inefficiencies in the lunchbox design: the lunchbox itself is a more complicated and expensive bit of hardware than would be required for a dedicated 8-channel rack box, then you have to pay for 8 different front panels, which are significantly more expensive in total than a single large panel, the power supply has to be sized for full spec even if the modules you select won't need that much power, etc.
Also I think that due to the limitations of the format, most of the modules I've seen are not as good ergonomically as normal rack gear: switches are smallish and crammed together, for example.
Then sometimes you see a design that just shouldn't have been done in a 500. I saw somebody had done a tube amp; the obvious limitation being the lack of a high-voltage rail, so a switching circuit must be added to generate that rail. That can inject noise into audio, which a designer can compensate for if they know about it. This particular unit has a full internal metal case, possibly because of the need to shield surrounding modules from EMI those wouldn't expect (if the circuit uses an inductor, which I don't know for sure but I might guess). All of that adds cost that doesn't exist in a dedicated rack tube amp.
So it costs $1,000; to me that falls under the category of brilliant technical accomplishment that isn't very practical, especially compared with a regular ol' 1u two channel tube amp--$2,000 is a lot of spendin' money.
So shop carefully . . . if you need a one or two channels of a bunch of different stuff, maybe it makes sense. I fit eight channels of more of less the same thing into 1u, that keeps me happy.
