Well, it's a bit harsh to say they are almost perfect and then say you served in the Air Defense. I did so too for years, any be assured, neither a .303 nor a 3,5 cm tracer will ever look like this.
It is a small dot of light flying away from you, nothing more. No lasers, depending on the round no smoke and definately not any shake,vibration or spin to it. A tracer round also does not have a ray of light sticking out it's back.
That's my issue with them: they are not only to thick but also way too long. I doubt the tracers 65 years ago looked that much different from what they do nowadays. Well, at least they got the colors right
*EDIT* This is by the way not meant as insult or a whinng post on what's wrong with CloD, however it's a sim, it should try to model reality as close as possible.