Dense materials like stucco and concrete will attenuate TV signals more than lighter materials like wood and asphalt. Wire mesh should shield out near 100% of TV signal.
But attic antenna performance is very unpredictable. Your report is favorable. If you want to try it, it might work. Up to you.
Both are good antennas. RCA does not publish technical data on the ANT751, so it's hard to compare quantitatively. The distances given are just advertising. Personally, I think the C2V is in a different, higher class from the ANT751. But the ANT751 is a great value for the price, and a good choice for many people.
I repeat my advice from the other thread to buy a cheap antenna, a long cable, and move it around in the attic and on the roof, to check reception.
You might look around for a local retailer that you can buy from, in case you want to return the smaller antenna and go bigger.
http://www.walmart.com/ip/RCA-Suburb...-Mast/10828410 Or if you fail in the attic, any of these antennas would work fine for you on the roof.