A few install questions
 

I have replaced individual components before but am going to install my first complete new groupset, it will be an Ultegra 6700.

1- Shift cable routing now goes under the bar tape and can be in the front or rear of the bars, is there a difference performance wise or just personal preference?

2- My FD now has an inline cable adjuster and with the new cable routing I will lose that how can I get a cable adjuster for the FD?

3- Am going to use an 11-28 cassette and for chain length the instructions say add 2 links, add two links from what, from when the RD is verticle in large ring small cog? That part is a little confising to me.

1) Housing routing on the bars is a personal preference.
2) Are you saying that on your previous group the barrel adjuster was up at the brifter? There are usually housing stops on the down tube and on many road bikes the barrel adjuster is there. I just built up a bike with 6700 CD and it works there. You might need a different barrel adjuster.
3) The circumference of a 28 is larger and a 24 so the chain length from a standard or triple setup needs to be 2 links longer or the derailleur travel will not work correctly. But if you are changing large ring on the crankset from a 52 in the front to a 50 (typical compact setup) it is probably even.

1. Some people say the bigger radius on the back of the bars will produce less drag so your shifting will be better. Some people don't have a problem either way, but if I were building up new, I'd just run the shift cables on the back to avoid having to undo and rewrap everything if there happened to be a problem.

2. You can just insert the inline cable adjuster in the middle of the cable housing. For example of instructions: http://jagwireusa.com/images/uploads...structions.pdf

3. I usually use the big-big method indicated at Park Tools website: http://www.parktool.com/blog/repair-...-length-sizing but then route through the RD and see how much it is pulling it. I only run 53/39 up front and never cross chain small-small, so I never check whether that comes out okay without rubbing on RD cage parts.

I want pics when it's done! :)

Thanks les and milkbaby after reading the parktool info it was clear that the chain length is determined without routing through the RD which for some reason I wasn't seeing clearly in the shimano instructions which after re-reading was clear, it for some reason just wasn't registering in my head.

that may be true, but be careful where you actually place the cables. i did this last time i installed new cables and really screwed it up with the result that the cables were right under my palms, especially out toward the hoods. extremely uncomfortable. just re-did it and put them on the front of the bars, and it's much better. of course, i probably could have just moved them farther down/back and accomplished the same thing.