As mentioned, there's lots of information on the forum about the 6501 system 7 and the 700 already.
The OP had another question, should he consider anything else? My opinion is that there is nothing else in the Xerox 700 & KM 6501 system 7 price / performance range, although the Xerox 2xx range is well worth a look if you understand it's limitations.
Of "The Usual Suspects", there is only Canon left and they don't appear to have a directly competitive product (at 14ppm the ImagePress C1 is too slow for many applications). I think the MGI machine is quite a lot more expensive and nothing else (i.e. Toshiba, Sharp, Ricoh) currently makes a competitive machine in this area.
It would be useful to the OP if anyone who knows any different could post here?
I suppose that the OP might also want to take a look at the KM 65HC (High Chroma), which is apparently now released. I'd love to know how people are getting on with these and what applications they are finding that can justify the price hike over the standard machine. If the OP is contemplating photobook printing, I suspect the 65HC might be a a really good fit there.
Finally, this issue of saying that the KM "is good only for text weights" is a little overdone and I think could be a bit misleading to people researching machinery. A 6501 will happily sit there all day duplexing and stacking 250gsm (sorry, I don't know what that is in "American", maybe someone will chip in). 300gsm must go to the top tray, not the stacker and will only run simplex. It will not run at the full 65ppm on heavier weights. A Xerox 7000/AP or 8000/AP will duplex up to 300gsm, and run at their rated speeds, as will the VP versions of the Canon 6000/7000. However please be realistic! These are several times the price of a 700 or a 6501 and the OP did not ask us for a comparison to a machine costing 3-8 times the price! We run a single 6501 at well over 100,000 SRA3 impressions a month and I know we are nowhere near the higher volume users.