Artic Silve 5 is a good TIM, but it got obsolete because of two things:
1 - It is very eletrically conductive.
2 - It need a lot of time to seat in properly and deliver best performance.
The only thing that was a problem for me was the conductivity. I wonder if they got rid of this issue with AS7.
Probably they didn't:
Made with 99.8% pure micronized Silver
62% to 65% Silver content by weight
Superior thermal conductivity. Greater than 7.5W/mK.
Temperature Range is -40C to >150C
Arctic Silver Thermal Adhesive is a permanent adhesive. Components you attach with
Arctic Silver Thermal Adhesive will stay attached forever.
They would be shouting it over our faces if it wasn't thermal conductive, and all that silver doesn't really looks safe between circuits.
Well... this could only be an issue if your not careful enought when appling - I am not.