Vista Compatible!!
After long, hard hours on different days, I decided on this interface for my first home studio. The MAIN reason I purchase it was because it was a USB powered interface and it works with Vista (32 & 64-bit). THANK GOD! After doing my research I've found out that most of everything doesn't work with vista when it comes to recording. lol I haven't used it on my Dell XPS M1530 Laptop (Vista 64-bit) yet because my software program (Magix Deluxe Studio 12 [Old Version]) doesn't open on it, but this works on the Toshiba (Vista 32-bit) with no problems @ all. This is my first home studio so I don't have much to compare it to (other than other home studios I have recorded in) but it works very nicely with mine. There were a few issues FOR ME (when running it on XP via Dell Inspiron 1150) with the Digital software I was recording on (Magix), because you have to set the software program's settings along with your windows settings to default the hardware in order to get it to record/playback (which I learned after calling Edirol). Which I didn't have to do when using it on the Toshiba. I don't use the build in effects, because I use the software's, but I guess it's good to have just incase. Overall, good product for what I need it for (just vocals in a home studio).

Nearly perfect for the price.
As has been mentioned, there is a tiny bit of noise with the mic pre amp, which can be avoided with some extra attention to levels. Moreover, the tube sim (on my unit, at least) introduces an unacceptable amount of noise for pro-level narration (even using an XLR condenser mic). That being said, the ability to turn a 0 netbook into a 160GB mobile recording station is simply awesome. It also comes with the Cakewalk LE suite (which is quite good), but for low-overhead recording, just pair this with Audacity and the downloadable USB driver package from the Edirol site, and your Acer Aspire (or other netbook choice) is ready to go. No power brick needed, USB powered! Now you can trundle off to find a supremely quiet nook somewhere and have a virtual sound studio at thy fingertips.

Small & Versatile
I'm just an amateur musician. We make our own backups and my goal was to be able to use the Ketron SD2 midi sound module for both input and output via the laptop. The UA-4fx does all that we need via the 2.0 usb port. We had to buy midi and audio cables but they are very inexpensive. There are front jacks for mics and headphones. The instructions will be a challenge for me to learn the effects but that's because I know next to nothing about sound. I mainly bought it to get the Ketron output which is top quality midi sound with upper banks as well.

Great versatile interface
I don't know too much about audio recording but this hardware does pretty well. Setup was fairly easy just follow all the instructions they give you, installing driver before plugging in...that kind of thing. Use is easy too the manual even gives you schematics for different recording sources. It doesn't like powered pickups (bass guitar at least), alot of tweaking is required so you don't have clipping even though the meter will not be in the red zone. The XLR connected mic sounded perfect. Software is crap-lots of pops and noise even though I checked everything like connections, drivers, volume, gain, etc. but no luck...then tried windows sound recorder and it sounded perfect. All in all its a great tool to make your laptop a studio on the go-just might need some better software.

Works great under Vista x64
Bought an E-mu 0202 and returned it after one day because it was horrendously flaky under x64.

Ordered this instead, and it's been rock-solid. Sounds great, easy to use, and having an actual LED meter on the thing makes setting volume levels for recording much easier.

The only way I could see improving this device would be to ditch the effects (they're amusing, but I don't actually use them), make it work in 96khz mode for both recording and playback simultaneously (right now you can only do one), and make the box a bit smaller.