Some folks will say they're a POS others will say no problems (I'm in the no problems crowd).
AFAIK, new installs are supposed to with the SWM LNB, as long as no more then 8 tuners are being installed. The way you can tell is if only 1 cable is coming from the LNB then it's the SWM.
Things to look for, your signal levels for the 99 and 103 sats should be in the upper 80's lower 90's, anything less have him repeak the dish. Also make sure that the two additonal support arms are installed to help keep the dish aligned.
If you're getting any non-DVR HD boxes make sure that they give you a H21 or higher, if you get a H20 you might be missing out on some future features that make use of the ethernet port that the H20's don't have.
I'd recommend that you also network connect any boxes with ethernet adapters in them. For the HD DVR's you'll be able to use DirecTV on Demand and Media Share, for the non-HD DVR boxes you'll be ready for when new features are released
. If you need to go wireless the HD DVR's have native support for the Linksys WGA600N adapter.