Disadvantage of plastic windows

If I have to compare plastic and wood windows, then the advantage of plastic windows are:

• they don't expand nor shrink, thus they don't need periodical readjustment as wooden frames
• they don't suffer from imperfections typical for natural materials
• it is easy to make holes into the frame for cables

The disadvantages of plastic windows:

• you don't see into the window frame. And sometimes the window is just a plastic frame, which is hold together with the glass. Once I have seen a plastic window which was left open for a week. And next week the glass slid out from the frame because the plastic frame couldn't hold the heavy glass for so long time. In another case the customer asked for a glassed wall and decided to make it from plastic windows. During the normal wind (30 km/h) the middle of the wall moved forward and backward by 8cm because the frame was armored just with a wire. I don't say that plastic frames are less rigid than wooden frames, that's not true. But when you decide to choose plastic frame, look at the armoring of the window - there should be massive pieces of metal, which can withstand a lot of force (nice trick - try to hang yourself on the frame, if the frame survives, you may have found a good frame).
• you don't know how durable is the plastic. The problem is that the manufacturers attempt to save the cost and put a lot of filling material into the plastic because the filling material is much cheaper than plastic. Unfortunately the filling materials often decrease the quality of the compound. The common problem is color instability (white turns into beige or grey - just look at your old PC to get the idea), cold problems (plastic can get fragile or porous in cold) and aging instability (simply some plastic doesn't last long, for example Tesco bags are designed to last just one year and then they turn into ash).
• while it can be good that you can easily make holes into the frame burglars abuse it as well. They make a hole into the frame, find the lever from the handle, pull the lever the right direction and the window is opened. It's easy (you just need an accumulator screwdriver, a headlamp and pliers) and fast (it can take 5 minutes for unskilled labor, 30 seconds for a professional).