UPC also has this portable programmer available (Simply Automated and PCS make them) to allow you to program devices without a PC. Also, a HAI panel can program HAI UPB switches without a computer.
I had a large X-10 installation and have switched to UPB. My X-10 switches were getting old and wearing out, so it required a change. UPB switches can be in the $55-75 range which is on the expensive side, but like I say, Frys carries a "cheaper" switch from Simply Automated. Its funny because the Fry's switch is labeled with a different model number than the US11-30 Simply Automated Switches that cost about $20 more, but they both are actually the same thing. UPStart software recognizes the differences, and restricts the cheaper switch to a single paddle, whereby the US11-30 switches support two paddles.
UPB is nice because, once set up, it can do a whole lot without any controller. Its been pretty reliable, but you most likely do need a bridge in your panel box, and there are lots of tricks to this.
If you go with UPB, be very careful if you decide to go with the UPB Simply Automated remotes. They are junk in my opinion. Plastic case that deforms when installed, and they couldn't even figure out how to make the remote's green LED match the color and brightness of their normal switch LEDs. There must have been some language barriers in Taiwan when these were build. The solution is simple. Use a regular switch instead (w/o hooking up the load) and link that switch to any other switch. This means you can change the linking with programming, which is pretty cool, so your remote can now be a remote to any switch in your house.
On the switches, I think the HAI UPB switches seem the most solid and have the best feel, but they are a bit more expensive. The Simply Automated switches have changable button configurations, which is handy, but the switches have a very cheapish click feel. A few other companies now make switches also.
UPB works fine with X-10, but you need to remove any X-10 repeaters, and add a UPB bridge which works for X-10 as well.
UPB has many types of switches, and one of the best features, in my opinion, was that many switches can be set to dimmable (for regular lights) or non-dimmable for ceiling fans and fluorescents with just some quick programming. Nice for someone used to different X-10 switches for dimmable and non-dimmable.
Would I do it again? I think so. Z-wave has lots of options so that may be an alternatives. Insteon I'm not so sure about because only one company supports it, so if they ever discontinue, ...