I've got the Marantz PSD230--paid about $450 for it two years ago when it was new. I recommend it--if only I had this when I was learning 5-string banjo!
It's great for figuring out leads quickly via looping. You can tune the cd to your guitar, slow it incrementally to half tempo without key change or change key if you want.
The new model you're looking at adds recording & CD burning to the PSD230 feature set BUT at twice the price.
Not worth it IMO--too many great 16+ digital track recorders/burners out there for under $900 that provide you with incredible home recording capability.
Check out
www.janetdavismusic.com for more on Marantz gear.She's got the PSD230 for $449.00. :)