The Pro & the HS are 2 of the best strings released in the last couple of years. The feel for a poly is brilliant, and just does everything really well. Gave it a good run today in a BLX Blade 98 and forgot the great comfort & nice power it gives, especially when you really rip into a top spin down the line shot.
The main difference I found between the HS & Pro was the HS was a slightly firmer feeling string but played pretty similar.
Organix 9 - M: Klip Armour 17 X: Alu Power @54/50, M2 Pro @ 52/50