Everyone has an opinion, valid or not.
The f/2.8 70-200 L lens is a standard pro lens.
But that does not make it right "for YOU."
Example, for ME, while I would like a Nikon 70-200/2.8 lens, it is a heavy expensive lens. The f/4 version, is half the weight and half the price. I did exactly what Derrel said, and bought the lighter f/4 lens, and my back and arm are glad I did.
To follow on from Derrel, think about the size and weight of the 70-200/2.8 L. Is it something that you would be comfortable carrying around a lot, or will it end up sitting on the shelf at home, because it is too heavy and big to carry? For me, big/heavy lenses (like my 70-200) are specialty lenses, for specific shoots. They are too big/heavy to leave in the camera case and carry around, unless you are 20+ years younger than me and in good physical condition.
The 70-200 L is designed for a FULL FRAME camera, not a crop camera. If your friend shoots a Canon FF camera, he likely has no reference for what a crop camera needs, because he is thinking in his FF world.
On a M series crop camera, the 55-200mm, would be close to what a 70-200 will deliver on a FF camera.
When you put a 70-200 on a crop camera, the short end is sometime too long for a crop camera.
I use a 70-200 on a Nikon crop camera, for sports. And many times, I find the short end too long. I would love the short end to be down about 50mm, which is where your 55-200 is. But that is for how I use the lens.
How YOU use the lens may or may not be different from me.
The 55-200 is a companion lens to the 18-55 lens.
The 70-200 is a companion lens to the 24-70, both full frame lenses.
But there is nothing to say that you cannot companion the 18-55 + 70-200 (except the size and weight of the 70-200).
While f/4.5~f/6.3 on the 55-200 is somewhat "slow" aperture-wise, it is "good enough" for daytime shooting.
I have no issues using my similar speed zooms, during the day.
As for image quality, yes the L series lenses is better, but will it make a difference to you?
The images from my pro level 70-200 are clearly sharper than the images from my consumer level 18-140 lens, but only if you look hard enough or crop deep enough into the image. For a 4x6 print of the full frame, you can't tell the difference.
If you make BIG prints or crop deeply into the image, then you may see a difference.
There are MANY different lens combinations you can make. Some make sense, some do not.
Example, here is a 3-lens kit that on the surface does not make sense.
18-55 + 55-200 + 18-150
On the surface it looks like there is significant overlap/duplication of focal length between the 18-55 + 55-200 and the 18-150.
However, in actual use, I find that I may have a use for all three lenses.
- 18-55 is a nice lens for casual family photography. It is small and light.
- 55-200 is a nice sport/longer lens and companion to the 18-55, and has a bit more reach than the 18-150.
- Although for reach I would use the longer EF 70-300 IS. But it is not a small lens.
- 18-150 is a nice GP lens when you don't want to swap lenses, like travel.
- I have and use the similar Nikon 18-140 as my GP lens. I found it to be a tremendously versatile lens.
- But, I found this class of lens is bigger and heavier than the 18-55, so not as easy to use for casual family activity. The 18-150 looks to be about the same size as the 55-200. I have both a Nikon 18-140 and the smaller lighter 18-70, for that exact reason.
- Once you have this lens, the 55-200 will probably be used less.
What I would get is the 22/2 or 32/1.4, for low light photography. But only if you have a need for it, you may not.
You should sit down and look at YOUR needs (what and how you shoot and want to shoot, now and out a couple/few years). Then budget and plan out a lens landscape for yourself.
Example, if you have a child in elementary, middle or high school, are/will they playing sports, and what will you need to shoot their sports? High school field sports at night is very different (and harder) to shoot than middle school sports during the day. High school night field sports is where that fast EF 70-200/2.8 lens comes into play. And for gym sports, maybe the fast 32/1.4.
Gud Luk