First of all, I have had some issues with the instrument input of the Scarlett 2i2, namely clipping. There are other users who have stated that they never experienced this issue, but for me it just wouldn't work, so I returned it. I have tried it with a couple of my electric guitars: one with high output pickups, and one with medium output pickups, both of them were clipping on my Scarlett 2i2, even though I turned the gain all the way down. There is no pad either, so you cannot lower the input level at all, which for me was enough reason to return it.
On the other hand, I really did like the Mic pres on the Scarlett 2i2, they sounded quite good to me, nice and clear, transparent overall. Of course you could run your instruments through a DI box, but you would have to get a decent one, and I personally don't like what the cheaper DI boxes do to the sound. Good DI boxes, however, are quite expensive, and I would just choose an interface that would not clip in the first place. In the end it is all about trying it out; like I said, there are people who have had none of these issues, and perhaps I just got unlucky, but I felt I had to share my personal experience about the Scarlett 2i2.
Finally, should you decide to go with the Scarlett 2i2, I can highly recommend getting a pci / pci-e USB controller, because in my experience, that will make it run much smoother. Some computer chip-sets are just unreliable and you will not be able to drop down to the lower buffer settings on the audio interface. I have tried with various USB ports on my computer, and I was unhappy with the latency, so I decided to install an extra USB controller, and it worked so much better! I have tried the Scarlett 2i2 with Samplitude Pro X, and a free version of Ableton that came with the interface.
I hope this information will be useful to you.
Kind regards,
