csyberblue pretty much got it, the newer DW6000 is a big improvement over the DW4000 (software based), there is no software on the computer anymore, speeds are more consistent, stays up longer (rain/ice) and its a straight ethernet interface now (acts as a router already with the basic service so use a Access point or switch for sharing it, not a router (unless you have a static IP, then you want a router

)).
Basically, the standard service will get you 500 - 1000 kbs down, 10 - 40 up, lag is around 700 - 2100ms, if you exceed 169 mb in an 8 hour period it will slow you down to dial-up speeds.
Anyway, bottom line is that it is a huge improvement over dial-up for your basic web browsing, the occasional file download, etc., It doesn't play nice for gaming (due to lag in the 700ms -2100ms range), VPN's (due to the design of the system, it will work but at dial-up speeds), etc.
When/If you have it installed, make sure they ground it (ground block with both cable hooked to it grounded to a legal ground) and make sure your cross-pol is a solid pass, not 1/2 pass, 1/2 fail.
Good luck,
WTT (DWay/DTV/Dish Installer)
Forum on Dway Here