the only thing i'd like is another set of rubber tubing - in case the first set breaks. but then again - I'm a nut and I go for things like that
I'm a recreational swimmer and use the paddles to get a better workout. A paddle size one larger than suggested by the weight chart has been better for my purposes. I haven't felt any shoulder strain and use the largest paddle size 5 days/week. I have been extremely satisfied with this product.
I purchased the Black (XLarge) based on the sizing chart - tho needed to get the XXL. It still works well and provides good benefits.
The swimmers find them easy to put on. Comes in many different sizes.
Just started using them, and they've helped improve my form already. I found that it naturally made me stretch further out and elongate my body. It also forces your pull to be more correct. No significant strain felt in/on either shoulder.