Originally Posted by Rozroz
if that's true then it pretty much closes the case, doesn't it?
Not at all. People dont just use strings just because they feel good. They are looking for a predictable response that enhances their game. What if you prefer to play at a tension in the lower 50s since the trajectory is better for your strokes? Well in this case it will be a lot tougher to control a multi or syn gut in that situation.
Also, the spin and control from polyester is substantially better and this translates to more confident hitting on court. As we know, tennis is all about mental focus and executing under pressure.
So while you can definitely play with cheap syn gut, you will notice a rather big difference at the 4.5 level with poly even just in the mains. That difference will result in an improved on court performance for many players.