I just threw away a couple of early ethernet cards with BNC connectors for 50 ohm coaxial.

Up to 10... nice...


The cable is more robust, so I am all for it...
But when I hear that the cable companies will be involved in in-house cabling, that frightens me.

I have tried using a technology that uses provides ethernet over mains wiring. Up to 14Mbps. Just plug in your router in a study, and then plug further boxes in around the house for PC's. Worked a treat. I have now seen some that do over 90Mbps. Even better.

35 five years old??? It's most likely daisey-chained wiring (not good)... there might be some funky buried splitters (bad), back then electricians ran the cable, and used RG59, and it doesn't meet current standards (bad)... Plus if they did any splicing, and the splices are buried,(sometimes happens), thats not good either, because back then they used pliers to squish on the "f" connectors = really bad & leaky connections.
Although you have tried wireless, recently some really hip stuff that allows you to stick in repeaters (in the dead or weak zones) of the house, so even a big home can be sucessfully set-up.
It would just be tempting fate to rely on the old TV wiring, unless the home was remodeled and rewired wsithin the last 15 years or so (by a really concientious electrician, who knew how to properly slice and terminate TV cable)...
I work in an area with a lot of really nice, well built older homes, but the wiring is horrendous.
I'd be cautious of an installer who jumped into that without reservations... Another thing is that a REALLY good installer, knows a lot of the tricks of the trade for doing what --- to the average guy --- seems like magic in terms of getting new wire into walls, with minimum wall damage (if any)... A lot of the old-time security system installation guys are sometimes really talented at getting wiring from point A to point B without ripping up the place!
The bottom line is... there is a slim chance you could fire up things on the old cabling system, but it probably will have some problems here and there... Personally if I were the installer and you wanted to use the old stuff, I'd ask you to sign a waiver, so if there are problems I would be coverd.