I bought an ION turntable a couple of years ago, and quickly found the software that came with it was next to worthless. The manual that came with it actually suggested using Audacity, and that's what I've used to convert LP's to CD's since.
And you don't actually need to have a USB type turntable to do it. All you need is to route the output of any turntable to a pre-amp (or amp) and then sent the audio out to the computer via a mini audio jack. Audacity can handle the rest. Although, I've continued to use the ION turntable because it's slightly more convenient than using my full audio system with a good Denon turntable. The ION turntable is a bit cheesy, though - you can readily hear any movement on the surface the turntable is resting upon - it has very poor damping - and it comes through as a low frequency bump on the CD. So I may hook up the Denon for future conversions.
Audacity gives one ample opportunity to filter out clicks and other defects. I haven't used that feature much because my LP's are all in pretty good shape.
Best part, Audacity is freeware. It is not the most user friendly app in the world, but with a little trial and error I was able to get a fair number of conversions accomplished.
One thing that will help is plenty of hard drive space on the target computer, especially if you want to store MP3 encoded versions of the music to play on other systems, not CD's.