The Canon EF 55-200mm f/4.5-5.6 II USM Lens is very light and compact, focuses fast, has a good focal length range and is inexpensive.
There is a Canon Lens Chart floating around that lists the 55-200 II as weighing 3.4 lbs. I can assure you that a scale would require many of them to reach this weight. This is a very light telephoto zoom lens.
What you don't get with this lens is good build quality. The Canon EF 55-200mm f/4.5-5.6 II USM Lens has a very plastic-like feel to it. No distance window is provided. A plastic mount seals the low-end build quality rating.
One of my favorite qualities of the 55-200 II is its USM AF (Autofocus). It is fast and quiet. Well, at least the motor is quiet. The lens elements make a "thunk" sound as they make a poorly-damped stop in their focused position.
Although it has USM AF (Ultrasonic Motor autofocusing), the Canon EF 55-200mm f/4.5-5.6 II USM Lens does not include FTM (Full Time Manual) focusing. In fact, the 55-200 does not even include a manual focus ring. Manual focusing is accomplished by turning the extending portion of the lens barrel after switching the lens to manual focus. It works, but is not very nice - very cheap. To make matters worse, the 55-200 extends during focusing. If you do not have the lens retracted when it is removed from the camera, you must switch to MF and twist the end of the lens barrel to fully retract it. Of course, you could just leave it as it is.
The Canon EF 55-200mm f/4.5-5.6 II USM Lens' zoom ring is nicely sized and turns easily.
From left to right in the picture above are the Canon EF 80-200mm f/4.5-5.6 II Lens, the Canon EF 55-200mm f/4.5-5.6 II USM Lens, the Canon EF 28-200mm f/3.5-5.6 USM Lens, the Canon EF 100-300mm f/4.5-5.6 USM Lens and the Canon EF 70-200mm f/4 L USM Lens. The same lenses are pictured below extended to their maximum length.
Like most of Canon's consumer zoom lenses, the Canon EF 55-200mm f/4.5-5.6 II USM Lens is a slow lens with an aperture that starts at f/4.5, goes to f/5 around 70mm and to f/5.6 around 100mm. A mid-lower end 6-blade aperture is utilized in this lens.
The 55-200 II is not a good lens for close subjects as it focuses no closer than 3.9' for a low effective magnification of .17x.
Overall, the 55-200 II is not a great performer optically.
Sharpness is one of the disappointments with the 55-200 II. Reasonable sharpness requires at least f/5.6 or f/8 at all focal lengths. Vignetting is also noticeable until similarly stopped down - even on a 1.3x FOVCF body.
CA (Chromatic Aberration) is especially apparent on the long end of the focal length range. The 55-200 II shows slight pin cushion distortion at most focal lengths - again, even on a 1.3x FOVCF body.
If you have a Canon EF-S 18-55mm Lens and are very satisfied with its performance, the Canon EF 55-200mm f/4.5-5.6 II USM Lens might be a good complement for it. If you are looking for top optical performance in a similar focal length range, the Canon EF 70-200mm f/4 L USM Lens is excellent. The optical quality and build quality difference is very noticeable - the price is of course higher.