Hail of a deal?

[South County]

I have had a contract with a local roofing company for 8 weeks now and still waiting to get the house re-roofed. I called today and they said another few weeks. Reason? They can not keep the shingles "Tamko Heritage" in stock, but if I went with another brand they could get on my roof "much faster". Roofer says comparable brands are just as good as Tamko. Tamko has name recognition and everyone wants them.

Question - Has any one else used ELK or GAF brand 30yr shingles?

I can't tell if its a way for the roofer to use cheaper shingles and make more $$$ from the ins. co. or if GAF and Elk really are comparable [?]