Warning, long smartass and somewhat butthurt post coming up!
The question of the necessity of preview should be resolved. I've read on this forum and heard from several players how preview is an absolute must and it's impossible to play without it. I've even seen scientifical explanations why there needs to be one. I'd like to point out, however, several reasons why there is no need for preview and even more, how preview is an unfair and unrealistic advantage to those who use it.
My personal hosting settings are Elite + realistic + no preview, which in my opinion guarantee the most realistic, most demanding and most educating gaming experience. Elite controls require formidable footwork and allow for a better feel of the ball, and they also force one to pay the utmost attention to the ball. Realistic mode gives us a tempo resembling men's pro tennis and forces us to develop quick reactions. And no preview forces us to develop a feel and sense where the ball is landing and forces us to react even quicker! These are the settings that should be most propagated.
Now, at first let's discuss why no preview is unnecessary! A good tennis player (even if simply a computer gamer) should have good reactions and a mind capable of thinking of and sensing the ball trajectory without any external help. Ergo, helping icons keep the gamer from fully realising the full potential that one's mind and muscle memory has to offer. The scientific explanation that I've seen thrown around, that the ball leaves no shade so you can't see it and that the camera angle doesn't allow to realise where the ball's heading, that is wrong and misleading. First of all, there is a very minor shade, second of all, in reality the shade is also very minor, third of all, sometimes ball's are shanked or hit off the centre of the racquet so they land in an awkward position (think of Nadal's on the baseline shanks). What do you do? You either react quickly enough or you pay the price of bad luck
Now, why is preview an unfair advantage? The main problem is the return of serve. "Experienced players" use a thing called auto-positioning to perform the split-step that in real life is a predicate for playing a good return. But the preview icon moves the returner a lot closer to the spot where the serve is about to land, it also gives the returner somewhere around half-a-second more time to react. While this may not seem much, it is a crucial difference , when up against a player of good-enough calibre and thus a well placed corner serve or even a vicious body serve can be sent back with ease. Not much less of a problem is the preview icon on the rallies, once again the preview-user can react half-a-second quicker, since the preview icon appears as soon as the ball has left the racquet cords. It negates on a huge level the aspect of thinking man's tennis tactics, such as wrong-footing, wrong-footing with a slower topspin drive, body-faking, fake drop shots, fake slices, deep counter shots. This (and not the preferance of realistic over fair mode is the reason why we have so much ball-bashing and so little variety!
Now to the butthurt part. I can't host all the time, only when using a WiFi network where I'm able to open the ports by accessing the router. Most of the time I'm using my university campus hotspot and Ethernet cable. So when I'm hosting I win a lot of matches, sometimes simply due to my better reactions and operational ability. But when I'm joining games that especially have previews on (I have mine permanently disabled, since the real-life player in me can't fathom to use such a thing), a lot of the time I can't outsmart my opponents, I can't surprise them with sharp angled or body-jamming serves, since the preview allows them to automatically position themselves where I'm hitting and prevent me from out-manoeuvreing them. This is of course with opponents who play a good-level tennis but my purist interpretation tells me that remove those handicaps, and they will have great trouble.
Looking forward to constructive feedback and comments.