Tried firestorm and 55 pounds and I didn’t like it, it was unresponsive , a little stiff , had very bad spin and little to no bite at all.
But after listening to a friend to did firestorm at 48 pounds and read more review about this string on tennis warehouse forum, I decided to string it at 47 pounds.
At 47 pounds this string truely felt like its potential has been unleashed, comfort was great.
Mainly I noticed that the string-bed opened up nicely. What it now offered is a fantastic combination of immense power with great control.
At this lower tension the strings became a lot more responsive, providing me with much more feedback and snapping back effect. Spin was now above average for a poly!
Somehow this string keeps trampoline effect well at bay!
I really enjoyed its feel and I am now using it at 37 pounds. Trampoline effect is now much noticeable here, but the amount of comfort and power I am getting is definitely worth it all.
The string tends to make me hit flatter, so I did and I am playing even better then before.
37 pounds might seem awe-fully low but, because this string is extremely crisp , it did not become mushy at all.
This string excels fantastically at low tension, and I suspect it plays better for flatter hitters.
Only issues with this low tension are that , powerful slice shots are hard to use. ( Trampoline effect ) Control issn’t good for shots that are off center. Overall control is below average but still pretty manageable.
For flatter hitters I recommend 37 pounds – 42 pounds
And for players who hit more spin I recommend 45-48 pounds
((Update: 17 may 2015
Firestorm at 35-39 pounds is awesome but against better players who hit heavier and faster balls, this tension I find is too low, lacks control.
The thicker Firestorm has lesser trampoline effect and more control at low tensions.))
Update : 9 June 2015
This Poly is incredible, it is the very best polyester I have ever used.
The secret lies in its tremendous ball-pocketing ability which gives a ton of feel and control. The only other polyester string I have ever tried that has ball-pocketing this strong is Alu Power.
This string had emulate the fantastic effects at high tension, but the crosses must be strong at 3-5 pounds lower then the mains.
Also this string suits flatter hitters.