7-year old tires were likely the cause of your blowout, not what you put on them.
As for the Michelin Pilot AS3's, I too installed a set of these about 6,000 miles ago and really like them. The ride well and don't trammel on uneven pavement much at all.
Back to the tire age, there was someone or some company attempting to introduce a law that would force tires to be replaced when they reached 5-years old. While I think this effort died, it brings to light that most blowouts are caused from the tires age, and not necessarily external factors such as debris or tire pressure.
Here is a tech article on TireRack's website talking about tire age.
In other words, just because tires have tread on them does not mean all is well.