Good to see that it's been a good hit for you. I'm really surprised about the 1st serve.
My 1st has never been better, but I am also working on it with a great pro this year.
Also, one of our league players has a pro-speed 1st serve and when he switched to the 400T his serves quickly became unreturnable.
I hope you work it out. BTW we both play with leather grips.
Steams 99s, leather grips; 4G @58lbs; ZX 16 / marathon 15L @62lbs