Originally posted by audiojan
It should still be 10 speed Ultregra, make sure it's not 9 speed (for some reason, 9 speed Ultegra and Dura-Ace pretty much sucked…).
If it's really well maintained with newer chain/cassette/chain rings/brake pads/cables/housing, then $700 is ok (not great, but ok). The P2-SL is a very fast bike, even by todays standard. It's not overly forgiving though, so if you race on really rough roads, that may be an issue (although that can somewhat be negated by using 700x25's instead of the more common 23's).
I've only used 8 speed, 9 speed and 11 speed myself
(somehow I missed the 7800/6600/5600 series
), but my research indicated quite the opposite. All groups have their strengths and weaknesses, but a few reviews online say the 10 speed group was, in some ways, a step in the wrong direction, that was "fixed" with the 11 speed group.
Everyone has an opinion, and lots of online reviews are biased, so I take them with a grain of salt, but I like the 9 speed group so much that I've pretty much standardized it across all my "pavement" bikes; 2 tri bikes and 2 road bikes, with almost enough parts to "upgrade" a third, my older QR Kilo, from 8 speed to 9 speed.
My limited experience: While the D/A 7700 Bottom Bracket is a little sensitive and harder to set up, the Ultegra or 105 BB is a nearly bulletproof replacement. Some replacement parts are expensive, but things like cassettes can be found dirt cheap on Ebay. Shifting is smooth as butter with both DA and Ultegra, and everything has been very reliable for me. I have nothing against the newer
(or older
) groups, just wanted to speak in defense of the 9 speed groups, as they've been nothing but good to me.