To start with the windows were measured incorrectly by the installer and we ended up with a 1"+ gap at the bottom of our main front window that they filled with wood.
When they went to install our new window (not in an existing location) they were going to install it without reading the work sheet information; basically the installer was going to put it off centre and 12" too low. If I wasn't there to babysit the work it would have been a much larger problem.
The biggest problem with them has been this: because of damage during installation we didn't sign off on the job being completed. We were told we would be contacted shortly by the sales rep and the installers left. A week goes by, we hear nothing. I check my statement and they took payment off my credit card. This was without authorization, no signatures, and with my very clear instructions that the work was not yet finished.
So we didn't give up on them yet, we called in to the sales rep and explained the situation, followed his directions and submitted a service ticket, and two weeks later still nothing. Now I'm in the process of filing an unauthorized charge with my credit card because, well, I DIDN'T AUTHORIZE PAYMENT.
And to top it off, meridian sends out a flyer after their work is done offering 20$ payment to me the customer if I fill out a 10 star rating on homestars.com. So anyone reading 10 stars from meridian, be warned, those stars have been bought.