Slimline only has ONE circle thing

Hello,

I have the Slimline HD Dish, I've had it for about a year and I Almost Always have a good signal and hardly ever lose it. BUT I have noticed that when looking at others dishes, they have three circle things (sorry not sure name of those, possible LNB) facing the dish and mine only has ONE. Does this mean I am not really getting HD quality? When I'm on the HD Channels, it  always looks awesome and I hardly ever lose a signal.

But mine is the only dish I see with only ONE circle thing, everyone else with the dish I have has THREE.  Is this a big deal??

I would hate to have someone out here and then they switch it and then my signal isnt as strong when it wasn't even neccessary to change.

thoughts????