I personally think x10 still has a place.
Granted I am new and just playing with power line carriers but I spend ~$150 on some x10 gear on eBay 30 dimmers, cm11a, phase coupler. Thats right, 30 freaking leviton dimmer switches!!! This stuff is cheap, so cheap if it did make a mistake from time to time it wouldn't bother me. So cheap I know I could offload it locally and get my $ back, probably profit it I wanted.
Thus far I have like 15 of then installed and I haven't had a problem.
The software used makes a huge difference in x10 speed. Some were very quick, never instant but inline with a CF lighting delay. Some were noticablely slower (easyx10 - free - not exactly easy).
I was in the same boat, seeing all the troubles with Insteon, and Smarthome, the lack of zwave devices, the costs of everything. I thought I might just try out x10, thus far it's not as bad as many would lead you to believe, and it's dirt cheap.