I haven’t used the PreSonus Firestudio mobile, but the main selling point for it would be if you’re planning on tracking drums; although it only has two mic pres, it has an additional 6 line-level inputs that you could conceivably connect additional preamps to in order to track drums. If your main concern is recording vocals and guitar, I might recommend the Focusrite Scarlett 2i2. It’s about $100 less than the FireStudio and I’ve found the mic preamps in it to be incredible. It also comes with a set of VST plugins that I’ve found to be useful. If firewire connectivity isn’t a priority (it’s becoming a rarity these days anyway), I definitely recommend it.
I don’t have experience with Studio One but it’s supposed to be pretty intuitive to use. I’m not sure whether it sacrifices any tweakability to accomplish this or not. Sweetwater is one popular music retailer that have praised Studio One for its ease of use, but it’s a relatively new software (version two was just recently released), so it hasn’t been widely adopted yet. I’d recommending seeing if you can download a trial or searching for reviews online.
-Jordan
