Hey Tommy16, the first thing to know is, more perspectives are good to have. Your perspective is a solid one that comes from experience. The truth is, there are a large range of things that would be useful in this circumstance.
The biggest thing to look out for would be advice like: "Get a Schlager Carbon! It's the fastest!" Or: "Get the ZJK Super ZLC. It's the most expensive, therefore it must be the best!"
Recommending more caution is not bad. I would say, your info would be top notch if this was still 30 years ago. Why do I say that? The 38mm ball. I hit with one recently. For the longest time I thought, "38mm ball is just better!" I have nostalgia for it. But, in hitting with one with today's equipment, man those things are fast. All of what I am using, which for today's 40+ Poly ball is good control equipment, is too fast for the 38mm ball.
But then there is also the fact that the technique has changed so much. 20 years ago there was a lot more blocking and driving and most players did not loop from both wings to the same extent or even anything close to how they loop from both wings these days. So, even without knowing Werner Schlager's way of thinking about this, we can see that thinner rubbers are better for hitting and driving and thicker rubbers encourage a player to learn the contact for spinning the ball more.
But we can also look at one other piece of information:
I currently use the Palio Legend Blade (premade), the dawei super power 2008 on the fh and the skywing 729 friendship on the bh.
The FH rubber is a Chinese (Euro imitation) rubber. It is a good control rubber but it is designed to imitate the the feel of the older ESN rubbers. The BH rubber is a control Chinese rubber. I am not sure which Palio blade that is because it probably is not the Palio Legend 1, 2,3 or 4, or, I should say: at least I hope not. Those are ALC blades and are not inexpensive and probably not great for learning.
So he is most likely, already using something in the slightly lower quality bracket that is closer to what NextLevel first recommended anyway. The change would be a logical step towards equipment that could help him develop good technique for today's game.
In any case, the biggest issue you brought up that is truly worth looking at: those bad habits: coaching would be more important to avoid them than equipment would. And with a decent 5 ply all wood blade, there are lots of rubbers that would be okay.
But I think NextLevel has identified the first issue for anyone looking to improve from the level of a newer player, and that is learning the contact and technique for spinning the ball. And he has also identified the way to avoid developing bad habits and how to fix bad habits you have already developed: GOOD COACHING.
But different perspectives that have some thought behind them are always valuable.
Sent from Godric'sHollow using the ResurrectionStone