I double checked and on the addition I built myself in 1993 and I did use all Anderson windows and as stated above , all my sliders are Anderson. It looks like I have just 3 Pellas on the older part of the house. It jars my memory that two of them were an odd size that Home depot had available in Pella but Anderson was a special order. The third window is in the same room as one of the odd sized Pellas so I guess I decided it was inportant for the interiors to match. I also was wrong on how many more I need to do to finish the house. I am down to just 3 full size windows and a little half size one left to do. That's good!
Thanks for the replies Ross and Fly Rod. I'll be getting Andersons for the remaining windows. One of the good things about a forum like this on a striper site is you get honest answeres which are hard to get in stores etc because you never know who might have an incentive program or whatever going with a particular manufacturer on any given day.