Never ever strung below 55 pounds for playing purposes (gut, synthetic, co-poly or poly; full bed or otherwise). The lowest I've tried is 48 for testing but then it all boils down to personal feel.
No way its power is below R22. It is much lower compared to the current BLX PST 90 (not comparing to Barbies).
Control, feel, volley, power, etc. It's a total package. Do I miss BLX's serving prowess? Sure! But do I get push around by much powerful racquets? Heck no!
It is better to have it and not need it THAN to need it and not have it!
Lux Alu Pwr @60 lbs., & X-One Biphase 17 @65 lbs.