First, disclosure: I am President of a company that has sold over $100,000,000.00 of Marvin Windows and Doors over many years. Yes, there are occasionally issues as there are with any product, however, our overwhelming experience has been that installation problems are at fault. You may have hired an experienced, reputable contractor, but perhaps the carpenter who installed your windows was a new hire. Proper flashing and caulking and a perfectly plumb installation are all necessary for good performance. An inferior product installed perfectly will likely outperform a great product installed poorly. Before you pay your installer be sure you use a level and carpenter's square to check for level and plumb installation. Also check to see that proper flashing and caulking techniques are used. Marvin, a number of years back, had major rot issues due to a primer product made by giant Pittsburgh Paint. Other window manufacturers had similar problems, but Marvin is the only one that stood up and replaced the windows, while other manufacturers walked away.
Reviewer is in happy mood. This person is quite happy with product line and quality. Please contact the author of this review to discuss good quality of a product or service. Marvin Windows And Doors needs to read this review and look into the issue (if any) according to poster's claims.
Other people also mentioned a product or service in their reviews. You may find this information helpful for further shopping at Marvin Windows And Doors. You can also consider other companies suggested by the author: Pella, Andersen Windows or Milgard.