Many of you out there keep asking us, "what makes a good window". In my opinion, here is a real good chance to learn some basics about window construction and to know one more thing to look for in a window that has a good design. Eberry just pointed out one flaw with the handle for starters.
The photo below shows a window that has a similar side jamb profile to the previous photo, but has a dedicated sill...a sill that was made as a sill.
This factory has spent the extra money on sophisticated machinery to cut and weld dissimilar extrusions to provide you with a sloped sill that provides proper drainage and keeps the glass loss to a mininum. The sill is not being used as a multichambered gutter to get rid of water that leaks in through the snap-ins...because there are none.
In your window shopping, if you can distinguish between these two styles of window sill construction, that is one place where you can narrow your search on finding a decent trouble-free window.
One giveaway on detecting the difference is that on a window with snap-in sill pieces, the beveled screen track on the outside will look identical on all 4 sides. With a window with a dedicated sill, the screen track will look totally different.
Also, many of these type windows with snap-ins will have pocket sills, where the bottom sash goes down into a hole in the sill.
This is my take on sill design. I am sure there are plenty of installers as well as the factories that make them that might disagree with me.