+fyi, there are three seperate mods for the ua-5:
digi-mod: allows the ua-5 to run standalone, or in other words when it's not hooked up to a computer via usb. like mentioned above, if you are strictly using your laptop, there's no need for the digimod. keep in mind you may want the mod later if you move away from computer-based recording. oade sells digimod ua-5's for $295. if you have reasonable sodering skills there are clear instructions on how to do the mod yourself, so you really could pick up a ua-5 off ebay for very cheap and mod it yourself.
warm mod: oade sells for $500, the digimod is included in this package. doug oade replaces the analog circuitry with high quality parts to produce "warm" and what I would call a very pleasing sound. this is what I have.
presence mod: sells for $550, same thing as above but the analog replacement produces a more upfront "presence" sound if you will.
you can buy a digimod from oade and send it back for the upgrades later. oade will not, however, mod a ua-5 not purchased from them.
I wish I had a laptop for my ua-5, I'd love to be able to run 24/96 or 24/48.