Anyone done add-on gridlines or mullions for windows?

[american_mama]

Does anyone have any recommendations (or warnings) about kits to add gridlines or mullions on to windows? This is one example of what I am talking about: http://www.newpanes.com/

I want to replace just one single-paned window in our kitchen, but getting one with gridlines from the factory costs $180 more. Our contractor suggested an add-on kit instead, which I agree with, but he doesn't have any firsthand experience to recommend. The websites I found in a quick google don't look as reputable as I'd like, so any advice would be appreciated.

[gatorsmom]

Our last house was built in 1985 and had them on all the upstairs windows.' they were like wood frames that had little pins in them and you would fit them to the window and press the pins into the wood to keep the frames in place. They looked really nice. They kind of gave our house a richer look to it. Ours didn't have Velcro or adhesive like I saw on the website in your link. If I wanted to wash the window, I'd simply pull the pins out of the wood and the frame would come off which I could then set to the side until I finished cleaning the window. I'm not sure how easy that would be with these sticking to the glass. Just my 2 cents.