I have the AudioBox and find it useful and adequate. I use USB MIDI for my keyboard and so far haven't needed the 5-pin DIN connector, but I do have some older modules and still might, so I'm glad I have it. You do want some form of audio I/O other than your laptop ports. The only reason you might want more than the AudioBox is for more ports or more than the 48 kHz max sampling rate. It also gives you front-panel hardware control of input levels and separate knobs for headphone and speaker volume--very handy.
By the way, you get a bundled copy of Presonus' Studio One DAW software with it. It doesn't support Rewire (you have to have the full version for that) but it might be fun to play with; I've heard good things about it.
Windows 7 Ultimate x64, Reason 7, BIAB 2013
Intel i5 2500K 3.3 Ghz, Gigabyte ZX77X-UD3H, 16 Gb Corsair DDR3 RAM
OCZ 60 Gb SSD, WD 1 Tb Caviar Black 7,200 RPM HD
Zotac/Nvidia GeForce GTX 560 2 Gb, NZXT H2 "Silent" case w/liquid cooling
Presonus AudioBox USB, Behringer B2031A, JBL PSW D110 sub
Kennesaw (Atlanta), Georgia, USA
Last edited by ryszard; 2012-11-19 at 11:52.