Over the years, I have completely disliked using bonded windows, and here are my thoughts:
Disadvantages of bonded windows:
1. Reflecting heat in the summer and cold in the winter.
2. After installation, there is a chance that bonded windows could leak and require water testing.
3. Condensation can build on the windows, causing occasional dripping, especially in the winter. This can result in upholstery becoming slightly wet for extended periods of time, potentially leading to mold growth. In my case, one of my bonded windows has a subframe, causing water to drip behind the frame into the insulation and I have to place a towel underneath full time. (see pic)
4. Most bonded windows are tinted, resulting in less light, especially on rainy days and evenings.
5. Additional installations, such as curtains, thermal window covers etc.
6. Replacing bonded windows is difficult, require special tools and skills, and once again, water testing is necessary.
Advantages of motorhome-built windows like Seitz, Dometic etc:
1. Double glazed for better insulation.
2. Comes with built-in blackout roller blinds, flynet, etc.
3. Easy to handle and install with a sleek finish inside and outside.
4. Transparent for lots of light or can be purchased tinted.
5. Easy to replace in case of a damage.