Little Labs Multi Z PIP (Professional Instrument Preamplifier) is a versatile piece of equipment that is basically a DI box with a number of awesome added features that make it so much more. It is made up of analog parts, with connections for an XLR output, and a slew of 1/4" connections for instrument input, summing amp input, re-amping input, hi-z output, a balanced only expansion output, and another optional output. It also has a 1/4" input in the front for your instrument input as well. It isn't a rack mountable piece of gear as it sits in a box.
Using the Little Labs Multi Z PIP isn't very hard - the only confusion can be caused by making different types of connections and figuring out new things to do with it. So while doing a few basic things with will come quickly and easy, diving a bit deeper with it can take a few uses with it. In terms of control settings, there are knobs for level and input selection, which has hi-z, mid-z, lo-z, and speaker to choose from. It also has a few switches for controlling different routing options. If you're new to something like this, which I would imagine that most people would not be if you're reading this, then a manual might be needed, but I don't think that most users will need one.
The sound quality of the Little Labs Multi Z PIP is absolutely superb. It reproduces your signal in the exact way that you send it to the box. I've used the PIP with both electric guitar and bass guitar, both of which I found to be great options for it. I used it with an electric guitar in tandem with a guitar amplifier miked up, and then I blended the two signals after adjusting the sound from the PIP to my likings using signal processing and occasional effects. I've also used the PIP for re-amping, which is probably the most convenient feature, as it allows me to then send that original clean guitar sound back through an amplifier if I wasn't happy with it the first time or just want to try a different amp for a different sound. It makes the possibilities endless and extremely flexible!
If you're looking for a very handy little box that will allow you to make all sorts of useful connections and also offers up a great sounding instrument preamp, the Little Labs Multi Z PIP is probably the best one that you can get. The price isn't very cheap, which is why I'd really recommend this for professional studios, who will most likely be the people using this anyway. I'd urge you to check out the specs to see if it would be worth the price for your to get it for your studio.