I also have the Janome 1600P -- I do believe that one of the reasons I chose it over the DB was because the DB did require special needles.
I love my machine, but... It is more awkward to thread and the bobbin isn't as easy/accessible either. No snap on feet and am constantly changing the feet. Love the 1/4" foot.
But I would buy it again in a minute. I think it is a great machine for just straight stitching (piecing). No fancy stitches. It is just a workhorse.