Not all cable plant is created equal. In some areas--actually--in some parts of some areas, the S/N can be quite good and in others, the S/N quite bad. Whether the operator has upgraded plant recently can also be a factor, as well as what got installed by the prior operator (there has been a lot of consolidation in the industry).
As far as capacity, sure, a satellite provider can send more video channels than an old analog CATV setup. Most CATV systems are not "old analog CATV setups" anymore. And, newer CATV systems with digital have capacity that is competitive with satellite--if you are lucky enough to be in an area where Verizon is deploying FiOS, you will have more capacity than you know what to do with--its fiber optic cable to your house... B'sides, the satellite guys are running out of capacity too--both Dish and DirecTV keep adding new satellites to offer more HD and local channels (since most satellites "see" the entire continental US, they chew up a lot of bandwidth when offering "local" channels because those tend to get broadcast to people who will *never* watch them--can't see wanting to watch NBC's local broadcast for Billings, MT in DC (OK, this is a bit of a simplification b/c they can use spot beams to narrow the problem a *little* bit)). The drawback is that you need more LNBs to receive those signals--your antenna suddenly has to be able to "see" three birds instead of just one. Makes optimizing reception harder and some birds are better placed than others for reception by users in different parts of the country. The signal from the three also may tend to go out of whack more because the precision needed to "point" and get three birds has to be higher, hence more wind effects.
Given all of that, the "losses" inside your house are probably fairly inconsequential. If you have old coax in your house, like RG58, you might consider replacing it with RG6. If you have it running through a lot of splitters, try to rework the topology to get rid of them and replace those that you need with high bandwidth, low noise splitters. Do any inside wiring runs in ways to limit the length of the runs, as much as possible. Make sure connectors are tight--that does make a difference. If you do that, inside wiring have the same impact as between CATV and satellite. Frankly, if you do those things, your signal quality is going to then depend upon the quality of the signal fed to your house--what comes off the antenna for satellite (which may be impacted by factors beyond your control) and what S/N you get in your location from your CATV provider (which may be totally beyond your control).
You can't simply make assertions that "CATV rocks and satellite sucks" or vice-versa. Unless you want on-demand, in which case satellite does suck.
As far as capacity, sure, a satellite provider can send more video channels than an old analog CATV setup. Most CATV systems are not "old analog CATV setups" anymore. And, newer CATV systems with digital have capacity that is competitive with satellite--if you are lucky enough to be in an area where Verizon is deploying FiOS, you will have more capacity than you know what to do with--its fiber optic cable to your house... B'sides, the satellite guys are running out of capacity too--both Dish and DirecTV keep adding new satellites to offer more HD and local channels (since most satellites "see" the entire continental US, they chew up a lot of bandwidth when offering "local" channels because those tend to get broadcast to people who will *never* watch them--can't see wanting to watch NBC's local broadcast for Billings, MT in DC (OK, this is a bit of a simplification b/c they can use spot beams to narrow the problem a *little* bit)). The drawback is that you need more LNBs to receive those signals--your antenna suddenly has to be able to "see" three birds instead of just one. Makes optimizing reception harder and some birds are better placed than others for reception by users in different parts of the country. The signal from the three also may tend to go out of whack more because the precision needed to "point" and get three birds has to be higher, hence more wind effects.
Given all of that, the "losses" inside your house are probably fairly inconsequential. If you have old coax in your house, like RG58, you might consider replacing it with RG6. If you have it running through a lot of splitters, try to rework the topology to get rid of them and replace those that you need with high bandwidth, low noise splitters. Do any inside wiring runs in ways to limit the length of the runs, as much as possible. Make sure connectors are tight--that does make a difference. If you do that, inside wiring have the same impact as between CATV and satellite. Frankly, if you do those things, your signal quality is going to then depend upon the quality of the signal fed to your house--what comes off the antenna for satellite (which may be impacted by factors beyond your control) and what S/N you get in your location from your CATV provider (which may be totally beyond your control).
You can't simply make assertions that "CATV rocks and satellite sucks" or vice-versa. Unless you want on-demand, in which case satellite does suck.