Insulation with Install

Is choosing an installer who uses low expansion foam over one that uses fiberglass insulation that big of a deal, or am I am over thinking things at that point?

Sorry forgot to mention a little bit about the job. 55 year old house in Pennsylvania with plans to use Himark 800DX inserts to replace the original single hung wooden pane windows/aluminium storm windows. Thanks in advance for your input.

Foam is preferable to fiberglass on every level, but I still would choose the installer that is more proven and you are more comfortable.

As long as the connection to the home and the insert is sealed, fiberglass is okay. The issue is that fiberglass, when unsealed, doesn't do anything to stop air movement.

Maybe ask him if he would you use foam and inform him it is 2012. It is easier,faster and superior.