I thought the 6600 and 7700 (Horizon 7700) were comparable but it looks like the 6600 is smaller and I defintely don't want to lose any throat space. The throat space and extension table is the best part of my Espire!! The reason I am even thinking about getting a new machine after having this one for just one year is that it has been having problems in the bobbin area and skipping stitches and just seems unreliable.